| If you can afford it, get the Haynes and the Bentley. It's good to have two sources of info when you're doing repairs. If you can only have one book, I guess get the Bentley. I had a Haynes manual for my Saab 900 and it kicked ass - way easier to use than the Bentley.
Does sound like the Idle Air Control Valve may be gunked up. Don't go so far as replacing it yet - just clean it with a good no-residue cleaner.
If you're check engine light is on, try doing the self-test to figure out the malfunction code.
Also, check your vacuum lines to see if any of them are cracked or otherwise damaged. | 
