I need some suggestions for a decent mic to use with my ThinkPad, which is the computer I'm using BiaB on.

I would also like some advice about whether I need a mixer or additional hardware for my projects.

I'm happy with my setup for making accompaniment tracks for an ensemble that I play for. Playing the tracks from a CD is working well for us. However, I would like to have the group record their vocals on top of the tracks to use for creating practice CDs.

I'm totally clueless about what additional hardware I should get.