HOW TO: Check old information on wowwiki:

I make this post to because there can be people that are new and don't know.

1. Go to wowwiki page of choice.
Example: http://wowwiki.wikia.com/wiki/Rogue_builds

2. Use history function. Down pointing arrow next to Edit button.

3. Pick a date that is from before wrath, usually late july/august 2008. (if you press the 500 it helps sometimes)
So you get: http://wowwiki.wikia.com/wiki/Rogue_...?oldid=1550680

Have fun learning, researching, reporting bugs and playing in TBC.

p.s.
Another source is of course http://www.wowhead.com/, more specifically the comments for each ability/spell/mob, etc.
Yet another is http://wow.allakhazam.com/ .
Finally you can use https://archive.org/web/ to search for old versions of many webpages you remember like ElitistJerks! Or any old guide pages that you remember were usefull for your class and has since been brought down.