There are multiple ways to use these: style, class, id. Examples:

<font style="font-size:11px; color:#eeeeee;"> </font>

<img class="some_classy_name">
In the header, within the <style> </style> tags, you'd have .some_classy_name {font-size:11px; color:#eeeeee;}

<div id="underage"> </div>
In the header, within the <style> </style> tags, you'd have #underage {font-size:11px; color:#eeeeee;}

With some exceptions, these can be applied to many elements (font, img, hr, p, table, td, tr, div, span, a, h1, h6, li, ul, etc.). Disclaimer: Et cetera is not an element.

Note that you can also assign the same styling rules for an entire category of elements. For example, you can write img{border:1px dashed purple;} within the <style> tags to assign this type of styling to all images (with the img tag). Notice that the absence of . and #. Of course, if you don't want to give all <img> tags 1-pixel dotted purple borders, then in addition to the general line you've just written, you can either assign a class img.otherclass{border:1px solid purple} or independentclass{border:1px solid purple} within the style tags. Or simply give specific images overrides by using <img style="border:1px dotted purple;">. This applies to other elements too.

Now that you know this, here's a list of many of the possible CSS properties you can use. I'm not going to annotate each one because I assume I've pushed your attention span already. Test and play around to see what you get. Have fun!

Font | Color & Background | Text | Div, Table, Image | List & Display | Position | Page Break | Misc

Font

Property	Example
font-family	font-family:verdana, arial, sans-serif
font-style	font-style:normal font-style:italic
font-variant	font-variant:normal font-variant:small-caps
font-weight	font-weight:normal font-weight:bold
font-size	font-size:xx-large font-size:x-large font-size:large font-size:medium font-size:small font-size:x-small font-size:xx-small font-size:larger font-size:smaller font-size:50% font-size:11px font-size:8pt
font	font: bold 8pt verdana,arial,sans-serif

Color and Background

Property	Example
color	color:red
background-color	background-color: pink background-color:transparent
background-image	background-image:url(seacucumber.jpg) background-image:none
background-repeat	background-repeat:no-repeat background-repeat:repeat background-repeat:repeat-x background-repeat:repeat-y
background-attachment	background-attachment:fixed background-attachment:scroll
background-position	background-position:top center background-position:bottom center background-position:left center background-position:right center background-position:0% 0% background-position:0px 0px (Other combinations allowed too.)
background	background: pink url(hippo.jpg) repeat-y

Text

Property	Example
letter-spacing	letter-spacing:5pt letter-spacing:-0.5px letter-spacing:normal
word-spacing	word-spacing:5pt word-spacing:-0.5px word-spacing:normal
line-height	line-height:15pt line-height:10 line-height:50% line-height:normal
text-decoration	text-decoration:none text-decoration:underline text-decoration:overline text-decoration:line-through
vertical-align	vertical-align:sub vertical-align:super
text-transform	text-transform:capitalize text-transform:uppercase text-transform:lowercase text-transform:none
text-align	text-align:left text-align:right text-align:center text-align:justify
text-indent	text-indent:25px text-indent:20%
white-space	white-space:normal white-space:pre white-space:nowrap

Div, Table, Image

Property	Example
margin-top	margin-top:5px margin-top:1% margin-top:1em margin-top:auto
margin-right	margin-right:5px margin-right:1% margin-right:1em margin-right:auto
margin-bottom	margin-bottom:5px margin-bottom:1% margin-bottom:1em margin-bottom:auto
margin-left	margin-left:5px margin-left:1% margin-left:1em margin-left:auto
margin	margin:10px 5px 10px 5px margin:1% 5% 1% 5% margin:auto
padding-top	padding-top:10% padding-right:20px padding-right:1.2em padding-right:10pt
padding-right	padding-right:10% padding-right:20px padding-right:1.2em padding-right:10pt
padding-bottom	padding-bottom:10% padding-bottom:20px padding-bottom:1.2em padding-bottom:10pt
padding-left	padding-left:10% padding-left:20px padding-left:1.2em padding-left:10pt
padding	padding:10px 10px 10px 15px padding:10% 10% 10% 15%
border-top-width	border-top-width:thin border-top-width:medium border-top-width:thick border-top-width:10px
border-right-width	border-right-width:thin border-right-width:medium border-right-width:thick border-right-width:10px
border-bottom-width	border-bottom-width:thin border-bottom-width:medium border-bottom-width:thick border-bottom-width:10px
border-left-width	border-left-width:thin border-left-width:medium border-left-width:thick border-left-width:10px
border-width	border-width: 3px 5px 3px 5px border-width: 3px thin 5px thick 3px thin 5px thick
border-top-color	border-top-color:crimson
border-right-color	border-right-color:tomato
border-bottom-color	border-bottom-color:gold
border-left-color	border-left-color:purple
border-color	border-color: red white blue green
border-top-style	border-top-style:none border-top-style:solid border-top-style:double border-top-style:groove border-top-style:ridge border-top-style:inset border-top-style:outset
border-right-style	border-right-style:none border-right-style:solid border-right-style:double border-right-style:groove border-right-style:ridge border-right-style:inset border-right-style:outset
border-bottom-style	border-bottom-style:none border-bottom-style:solid border-bottom-style:double border-bottom-style:groove border-bottom-style:ridge border-bottom-style:inset border-bottom-style:outset
border-left-style	border-left-style:none border-left-style:solid border-left-style:double border-left-style:groove border-left-style:ridge border-left-style:inset border-left-style:outset
border-style	border-style:none border-style:solid border-style:double border-style:groove border-style:ridge border-style:inset border-style:outset
border-top	border-top: thick outset pink
border-right	border-right: medium inset crimson
border-bottom	border-bottom: 1px ridge maroon
border-left	border-left: 5px groove purple
border	border: 1px solid black
float	float:left float:right float:none
clear	clear:left clear:right clear:both clear:none

* Note: margin: 0px 0px 0px 0px shorthand corresponds to top right bottom left (clockwise). Same goes for padding: 0px 0px 0px 0px and border: 0px 0px 0px 0px.

List and Display

Property	Example
display	display:none display:block display:inline display:list-item
list-style-type	list-style-type:disk list-style-type:circle list-style-type:square list-style-type:decimal list-style-type:upper-roman list-style-type:lower-roman list-style-type:upper-alpha list-style-type:lower-alpha list-style-type:none
list-style-image	list-style-image:url(listbullet.gif) list-style-image:none
list-style-position	list-style-position:inside list-style-position:outside
list-style	list-style: square outside url(listbullet.gif)

Position

Property	Example	Where It Can Be Used
clip	clip:rect(0px 200px 200px 0px) clip:auto	all elements
height	height:200px height:auto	div, span & replaced elements
left	left:0px left:5% left:auto	absolutely & relatively positioned elements
overflow	overflow:visible overflow:hidden overflow:scroll overflow:auto	all elements
position	position:absolute position:relative position:static	all elements
top	top:0px top:5% top:auto	absolutely & relatively positioned elements
visibility	visibility:visible visibility:hidden visibility:inherit	all elements
width	width:20px width:80% width:auto	div, span, & replaced elements
z-index	z-index:-1 z-index:auto	absolutely & relatively positioned elements

Page Break

Property	Example
page-break-before	page-break-before:auto page-break-before:always page-break-before:left page-break-before:right
page-break-after	page-break-before:auto page-break-before:always page-break-before:left page-break-before:right

Miscellaneous (Cursors, Links)

Property	Example
cursor	cursor:auto cursor:crosshair cursor:default cursor:hand cursor:move cursor:hand cursor:e-resize cursor:ne-resize cursor:nw-resize cursor:n-resize cursor:se-resize cursor:sw-resize cursor:s-resize cursor:w-resize cursor:text cursor:wait cursor:help
link visited active hover	a:link {color:red; text-decoration:underline; background:white;} a:visited {color:crimson; text-decoration:underline; background:white;} a:active {color:pink; text-decoration:underline; background:white;} a:hover {color:white; text-decoration:none; background:black;}
first-letter, first-line	p:first-letter{float:left;color:blue}