You need an audio interface. Did you check out the Zoom test (top of the list on the homepage)? There are also non-expensive solutions for guitarists and bassists from Line 6.
As for guitar stuff Line 6 is definately something you should check out. For recording also check out M-Audio Equipment. As for a mic that really depends on your budget. Are you playing electric/acoustic, both? For acoustic I would eventually recommend a condenser mic (Like the Rode NT Series or AKC C1000 and so on). Since you want to record singing as well maybe look into a large diaphgragm microphone...like the C3000 or the AT Series by Audio Technica (there are many more).