Jack's info on recorders in G, while spot on, could mislead novices. The "usual" keys for Baroque recorders as used widely in schools, and the consorts that they produce are (in descending order);
sopranino F
descant      C (also called soprano, in some countries)
treble         F (also called alto, ditto)
tenor          C
bass          F
great bass C


Cheers, Rowan