I picked up the collector's edition magazine of this list. It's in a great format, especially opposed to the website which takes a lot of clicks to get through all 500. The $12.99 magazine is no longer on newsstands but is still available (as of August 2012) on the web (try EBay).
The albums were initially ranked by 273 artists, critics and industry figures in 2003. A 2nd round of balloting took place in 2009 with only 2000's albums being ranked. Overall, I find the list to be very good. I think the double voting process skews the results against albums from the last twenty years, as opposed to if there was maybe only one vote, in say, 2011. As a result, the 1960's and 1970's are very well represented, especially closer to the top of the list.
More background about Rolling Stone's list can be found at the definitive source:
When looking at the list, it's very easy to nitpick details of the rankings. But my favorite aspect of this type of list is discovering albums, usually older albums, where I've heard of the artist or album but have never really listened to much or anything by that artist in particular.
There is an interesting resource if you do check out this list and find yourself in disagreement with the rankings. This link, also courtesy of Wikipedia, compiles 14 separate top album lists and ranks the Top 15 albums based on the compilation of the 14 different lists.
Not to be outdone, Purple Alpaca plans to put together a list of its own Top Albums of All Time. Yeah, it won't be 500, but we will be soliciting votes from folks in the Purple Alpaca community. Stay tuned.