Ok I will say one thing on this guitar amp thing.  If it's a tube amp you do need to get it to a certain point before it gets sweet.  But if you have a modeling amp (line 6, Johnson, Vox, Fender all make them now) then the tone is the same thru the entire volume range.  But our problem here is that guitar players think they are the band and they should be loudest.  They have not learned how to play with others.  It will NEVER change...  I've know very few guitar players who actually knew anything more than turn it all the way up....

George, You need a singer PERIOD.  You need to learn some covers and play for people or you can jut sit in the basement for ever and pretend to be a musician.  It does not matter how good someone is.  I'll take a person with average skills but a great attitude any day.

Studio Technologies

I agree with Steve about the traditional tube amp.  However, most amps have a channel and master volume..crank up the channel and leave the master down to get the "sweet" sound.  Or you can drape something over the speaker (blanket etc) to keep the volume down.  I use ear plugs everytime I play.  I bought them at Guitar Center (you can get them at almost every music store) and they are designed for use in bands.  I find the kind you get at work (foam rubber ones) cut out too much volume and makes it hard to hear, even the drums.

As to volume.. you best get some control of it at practice..if not when you get a gig you will be too loud there as well.  It is hard for a PA to get louder than a 100 watt Marshall head running wide open. 

Nice to see things really don't change over time.  Guitars and volume have been an issue since I first started playing (30+ years ago)  Dang am I old or what!