First, something easy you can do...
Always read the liner notes on your records. Read the credits. Check all the players listed, check the label, year etc. You may have no idea who those people are, but if you see their name on enough records, you will start remembering them.
When you go out to buy records, look at the credits on the ones that catch your eye. You might see the name of a bass player you like or something.
Also...
there's these books that I have that I find are pretty good references. There is a website too, but I like to have the books. I'll pay the money if it means I don't have to wait for a web page to load. Check them out here
http://www.allmusicguide.com/
They have biographies on many artists and info on all their albums. Each genre of music has it's own book.
Also, read the notes on some of your favorite hip hop records. If there's a song you like that has a cool sample, it might be listed. Maybe you can try to find that record or something and it will introduce you to some new stuff.
A good start would be to try and find some records on the CTI label. They aren't hard to find or too expensive, and for the most part they put out some dope music. You'll notice a lot of the same musicians are on a lot of the records.
If you're at a thrift store or wherever and they have records for cheap, I'd pick up whatever looks interesting. Not too much goes into it. They aren't gonna cost a lot anyway. Maybe you got something good, maybe you didn't. You'll start to pick better ones the more you do it though.
Peace