How to make your own custom PCB:
http://www.pad2pad.com/index.php
direct toner transfer:
http://www.fullnet.com/u/tomg/gooteepc.htm
http://www.pacificsun.ca/~robert/pcb/pcb.htm -for dummies, very good paage!
http://groups.yahoo.com/group/Homebrew_PCBs/ 
Built your own DSO ( digital storage oscilloscope) : 
http://www.fpga4fun.com/digitalscope.html
http://www.chocbar.demon.co.uk/
http://www.bitscope.com
http://www.johann-glaser.at/projects/DSO/
http://a26.lambo.student.liu.se/?section=hard&project=scope
http://members.ozemail.com.au/~dljones/files/dsoa_mk3.htm
http://www.ee.washington.edu/conselec/CE/sp95reports/guterman/final/scope1.htm
Electronic schematics and other goodies:
http://www.interq.or.jp/japan/se-inoue/e_menu.htm
http://www.commlinx.com.au/schematics.htm or
http://210.15.198.70/schematics.htm 
http://www.uslink.net/~cybercir/archive.htm
http://www.epanorama.net 
PIC16/18F bootloaders:
http://www.ac.ugal.ro/staff/ckiku/software/picbootloader.htm
http://www.htsoft.com/files/samples/bootldr.zip 
http://www.dontronics.com/rfarmer.html
http://www.voti.nl
http://www.circuitcellar.com/flash2002/honorable.htm
http://www.ise.pw.edu.pl/~wzab/linwload/linwload.html 
http://www.seanet.com/~karllunt/picload.htm
LCD to PIC interface info:
http://www.myke.com/lcd.htm
http://www.epemag.wimborne.co.uk/resources.htm
http://www.doc.ic.ac.uk/~ih/doc/lcd/
http://www.bobblick.com/techref/projects/projects.html
PC serial and parallel interfacing info:
http://www.beyondlogic.org/
PIC12C508 tricks:
http://www4.tpg.com.au/users/talking/10%20Tricks%20for%20508A.html
http://www4.tpg.com.au/users/talking/library_button-to-2Buttons-2.html
RS485 protocol:
http://www.national.com/an/AN/AN-1057.pdf
http://www.arcelect.com/485info.htm