SS.com is a valuable resource if you are serious about sports photography as a business. You can access much of the site without being a member which is pretty cool and can help a lot. The message board is readable without being a member, but being able to post questions is very valuable if you are a member. Also the ability to get to resources such as the guide, which has contact info for different venues and series is very helpful when looking to get info on an event or contact the right person for credentials, or just to find out of the place will have high speed internet connectivity and how much it might cost to get access to it. The sponsors also offer special pricing on products to members (I saved about $500 on a MkII vs. the best reputable online prices I could find at the time) and first rate and often expedited service to members as well since most are working and usually depending on product to make money.
Its a great resource if you are going to use it for all its got, ie. you are a working photographer that needs the kind of info and service it provides. If you arent, you can still get a ton of great info from the site articles and reading the message board until you are ready.
BTW, if you really want to be a member, just go for it. Worst thing that happens is you get a free critique from some of the best in the business as to what you need to do to improve the photos for the next time.