John,

You do indeed have an Anglo Concertina.

There's a nice introduction to the instrument here.

The most comprehensive site for Concertina stuff is www.concertina.net

Your instrument has 20 keys which means that you can play in 2 keys C and G (and their related minors) easily.

The more expensive instruments have an extra row of accidentals. Don't worry too much about that, it took me a year or so before I started feeling restricted.

I can't help you much concerning lessons or books as I pretty much learned by ear.

Do you play any other instruments? I could offer you better advice if you let me know that. Also do you want to play tunes or accompany songs?

Have fun

Ed