new imac owner questions

I have an imac running Tiger and I can't get my HP photosmart 7550 printer to work. I've downloaded and installed the proper software from HP and chose the 7550 as the default printer, still nothing.
Does anyone know of an e-mail program that will work on the mac and have the capability to have multiple identities with each of them having the ability to have its own address book?

Thanks

To have two identities, each with a unique address book, the simplest way is to create two separate users accounts in OS X. Each User can then have its own environment