Glossary of Immigration Terms. A lot of very specific terms are being used during the visa and green card process. Use this glossary to familiarize yourself with those terms to be able to understand the legal "mumbo jumbo" used in the communication with the various government agencies.
ImmiHelp.com/GreenCard provides numerous articles about the various steps and choices applicants have to make in order to acquire permanent resident status, written in plain and easy to understand English. The site also provides discussion forums, classified ads and visa/immigration trackers.
ImmigrationSupport.com/Permanent Residence provides guides in PDF format about the necessary steps of the green card process, depending on the applicants current status and non-immigrant visa. It also provides a newsletter that informs about recent political developments that impact the immigration process.
It may sounds funny, but try Yahoo! Answers. You can ask a specific question regarding your case and what you want to know. There are very quallified people answering questions there. Some are even Lawyers or work for the USCIS (and provide answers anonymously). Yahoo! Answers has a special category only for questions to immigration. Regardless of the answer you get, double check it yourself and don't follow any advice blindly.