Just listing some helpful roguecrafting pages I tend to frequent (most are from EJ):
Aldriana's Combat & Mutilate Spreadsheets - One of two spreadsheets that is typically considered to be the most accurate, and IMO is easier to use (especially the combat sheet).
Thaela's Mutilate Spreadsheet - As of 8/20/09, the updated version of the mutilate sheet. Based off Aldriana's, I believe.
Mavana's Roguecraft Simulator - The second of the two spreadsheets, this one is also (as the name implies) a simulator. This one is what you would want to use if you were using a HaT spec.
Pocket Guide to WotLK - Frequently updated compilation of helpful information for the raiding rogue. Very useful.
Aldriana's Rogue FAQs - A thread dedicated to providing answers to some of the more commonly asked raiding questions. Especially helpful if you're new to raiding as a rogue (but still excellent to keep up-to-date with even after).
Shadowpanther.net - A database of rogue gear, listed in order of upgrade. A useful quick-reference guide, but best when used in conjunction with a spreadsheet.
All of these pages have been immensely helpful to me over the past 4 years of raiding. The spreadsheets in particular are an indispensable tool. I highly recommend becoming familiar with them if you aren't already.
