Get a Dynamic....its good to start out with..... its good for bright vocals which girls usually have...even though a condenser mic wil give you better quality it cost alot of money for one....with a Dynamic you dot need much equipment to operate because condenser rely on phatom power for pre amps/mixers....

so get a Dynamic "Unidirectional" Microphone for like $25-$40 at radioshack
pZ