SelfPublishing.com (a/k/a Self Publishing, Inc.) is long established company in this business (you'd have to be to have that domain name!) and their approach to the business is in line with all of our best practices. Where they fall down a little is on the execution. Their products, like their website, are not executed with quite the level of professionalism we would like to see. However, if the author is careful in how they utilize the services, then they can end up with an excellent book.
SelfPublishing.com is an out growth, according to their website, of booksjustbooks.com, a book printing broker. If you give them your book specifications, they help you find the best book printer for your job. This adds a level of complication and cost to the book printing that isn't needed if you contact the book printers yourself. However, with this starting point, SelfPublishing.com is quite knowledgeable about the entire book publishing process. They do tend to lean toward traditional printing and distribution and don't really explain POD options very well.
The basic business premise of SelfPublishing.com is that an author who is self-publishing their book needs to control the process and hire professionals to help them execute. This is excellent and their services offerings are in line with this premise. However, the execution of some of the book covers, the lack of clarity on using POD vs. traditional print and distribution, and limited marketing guidance prevents us from giving them our full, unrestricted endorsement.