So I am playing in a 3000 point tournament this weekend. One of the guys who gives me the biggest problem is a skaven player. He usually brings 2 hellpits, and 2 or 3 lightning cannons. Any thoughts on how to combat this? Other players that will be there are dwarf, Ogre, VC, Wood Elves. But my biggest concern is this skaven player. If you have any ideas for me please help. Thanks
What an amazingly original Skaven list

to be fair though, they do lack real heavy hitters outside of Special and Rare.
Lore of Fire is garbage, don't take it. Removing Regen doesn't matter, you need to nuke the Hellpits early on.
Lore of Shadow offers both an Initiative reduction (Miasma) and a nuke (Pit, which only scatters D6" with the small template, so barring a bad roll you'll never miss). It also has Mindrazor, for smashing up heavily armoured units like Dwarves.
Lore of Light is going to be a big help against Skaven (going ahead of them with 'Speed of Light', chewing apart their pathetic infantry with 'Timewarp'), and also good for fighting High Elves (you need 'Timewarp' up to even have a chance in combat, 'Pit' won't work because of their high Initiative).
Lore of Life has 'Dwellers', which if combo'd with 'Enfeeble' from the Shadow Slann, will annhilate both Hellpits and entire units of Elves and Dwarves easily. Regen is also handy for when the dirty Skaven try to drown you in bodies.
Killing the Warp Cannons is going to require longer ranged measures. 'Pendulum' from the Shadow lore is handy for this, but Camo Skinks are also a good option. 'Pha's Protection' is also a good one to cast from the Light lore, as it forces your opponent to roll a 4+ to even fire his artillery.