Skaven is one of the largest races in the Warhammer world. They live in the underground tunnels that they dug. These tunnels extend from one end of the Old World to the other. These complicated series of tunnels can take them right under the Empire's capital of Altdorf, to the Dwarven Keep of Zuffbar. This is how the Skaven get to where their going. Skaven worship one God, The Great Horned Rat. Once thought to be one of The Gods of Chaos. Skaven are thought to be created by the powers of Chaos. It is said that Chaos created Skaven as an ally in the war against humans, but instead they broke away from the power of Chaos and started their own nation in the underground. Although they broke away from Chaos, they still use the powers of Chaos for their evil deeds. One such example would be that they have their own Greater Daemon, Vermin Lord. They also still have some troop types that would fall under the category of one of the Chaos Gods, like Censer Bearers and Poison Wind Golbadiers(Nurgle). So as you can see Skaven still have many ties to their creators.
If you are a Skaven player looking for some tips, look no further. Skaven are powerful in combat, so I would suggest to get them into combat quickly. Also, since they have low leadership, they have a special skill that lets them add +1 leadership for each rank beyond the first, not going any higher than a leadership value of 10. A troop type that would be good to get are Warpfire Throwers. They have the potential to do alot of damage as long as you roll good. One good tip for the Doomwheel would be, don't set it up close to your own units, because it can hit them too. Finally, some people might think that getting 2 or 3 Vermin Lords would be great. It would be, but don't forget those points come out of your character points, so spend wisely.
If you are looking for some tips on how defeat Skaven, then here you go. Skaven are alittle bit above average when it comes to hand-to-hand combat. So it might be a good idea to get some archery and wear down their ranks alittle bit before you charge them. Skaven have low leadership but have a special rule that gives them +1 leadership per rank beyond the first, going no higher than a leadership value of 10. So, in a way if you can cut down their ranks with archery, you're also lowering their leadership so that they can run easilier when they get defeated in hand-to-hand combat. Finally, the Doomwheel is very powerful if used right, so keep on the lookout for those.
I hope you found what you needed. You can E-mail me if you have any questions and/or comments.