Ave
Let me first start off by saying that Solomonic Magick deals only in small part with demons, those spirits in the Goetia and Theurgia Goetia, the first two books in the 4/5 books of the Lemegeton, the Lesser Key Of Solomon. The other 2 books deal with angels exculsively, not even mentioning the Greater Key of Solomon that deals only with angels. Secondly, if you want to get started on conjuring spirits, I've gone an extra few steps and found free pdf files to get you started, these are:
http://www.fratermd.com/magic/SummoningSpi...onstantinos.pdf -Summoning Spirits by Konstantinos, a training manual using mostly Golden Dawn type magick.
http://www.hermetics.org/pdf/grimoire/gkos1.pdf }
http://www.hermetics.org/pdf/grimoire/gkos2.pdf }--This is the Greater Key of Solomon, in three parts
http://www.hermetics.org/pdf/grimoire/gkos3.pdf }
http://www.hermetics.org/pdf/grimoire/arbatelofmagick.pdf -The Arbatel of Magic
These should be more than enough to get you started. And, if you find that you can get your hands on some money, get these two books, as they are the best on the subject:
The Secrets of the Magickal Grimoires by Aaron Lietch
Ceremonial Magic and The Power of Evocation by Joseph Lisiewski
Good luck, frater.
Ad Scientiam