i do most of my recording/mixing on a quarter inch tape machine...i'm looking to use my mac mini for editing/splicing/arranging various musical sketches...so i'm wondering:
a)is garage band 2 sufficient for this kind of thing, and
b)what is a basic interface i should look into? something inexpensive would be nice...just enough to import my songs.

There are numerous threads recgarding this very topic in this section as well as the 'hardware' section. There is a 'search' function you can use as well. if you type in the word 'interface' it turns up a wealth of threads and information with that very topic included in the body of said threads. i just did it. it was awesome! As for garageband im sure it will be more than enough to get you started.

softly,
sadpandas