Does someone have a good link to explanations of the differences

Between different socialist groups? I'm doing my darndest to understand as much of the politics of different organizations as I can, but...it's rather challenging. There is a lot of information to process, and with my reading list already stretching out years into the future, I'm having a tough time keeping up. Especially since I've only delved heavily into leftist politics in the last 6 months, and have only been in politics in the last 3 years.

At the moment, I'm working with the International Socialist Organization in Seattle. I'm not opposed to joining them, as I have yet to significantly disagree with their politics. A good part of the reason for that is simply that I don't have the theoretical background yet to really understand what I might or might not disagree with. I feel like some sort of explanation of the various groups and their similarities and differences might help a bit in figuring out whether my politics align with theirs or not.

Any suggestions? (Apologies for my wording, I've been a bit scattered between posts and essays and reading topics tonight).