Yep, currently the rulebook is in the 8th edition, which is the rulebook I've been using.
There definitely has been a bit of changes from 10 years ago (4th or 5th edition rulebooks)
The individual army books vary but most likely have been or one or two new editions in the past 10 years depending on the army. They, most likely, have quite a few less changes over the last 10 years than the rulebook... but definitely still have some changes and new units.
I'm not too experienced in 40k, I just know the bare minimum game mechanics. Ideally I would prefer to play fantasy over 40k.
Here's an online listing of the Warhammer Fantasy Rulebook 8th edition If you want to brush up on rules/changes and play a game.
http://www.scribd.com/doc/148271683/Warhammer-Fantasy-Rulebook-8th-EditionCan probably find a better one in color if you search online, but this one is pretty easy to read... just some of the diagrams might be harder to see because of its black and white.
You'll also need the specific armies book for whichever army your going to play which can usually be found online as well. If you wanted to play a high elves vs high elves match I wouldn't care... It would simplify the game since our units would both have similar/identical stats. Dwarves would be a great starting choice just because they don't use any wizards/mages, so you wouldn't have to worry about that part of the gameplay. But play whichever army you want. Orcs is definitely a solid choice too.
I'm "The Saint of Killers" on steam if you want to add me... msg me anytime you want to try to play 1 or let me know what time would work best.