The Lesser Key of Solomon is one of the older and most referenced books on the subject, and a good starting point, though it shows its age. You can find the seals, names, and specializations of the goetic demons in that book and others like it. Any ritual to summon the goetia should include a circle of protection in which the summoner stands during the ritual, and a triangle of evocation into which the spirit is summoned. Never summon a spirit into the circle with you, or into yourself. The Lesser Key treats the demons as evil entities, but a more modern and less Christian paradigm is that they are simply powerful spirits and not necessarily evil. They are however dangerous, especially since they are generally happy to come when called even by an inexperienced practitioner.
Some notes based on my own research:
* Always use the circle and the triangle to protect yourself, and construct them well. Do not cut corners.
* Never not allow the spirit to enter the circle, nor allow any part of your body to exit the circle or enter the triangle.
* Be polite but stern and absolutely unyielding.
* Do not offer anything in return for the spirit's services, even if they ask. As long as they are in the triangle, they are bound to serve your demands, unless you give them leeway, which you should not. Demands of sacrifices or other services from yourself should be politely but sternly refused.
* Always command the spirit to leave when you are finished, and do not exit the circle until you are sure that they have gone.
* You are more likely to perceive the spirit as thoughts in your head in response to your own thoughts, than to hear or see them physically, unless you have an innate talent or a lot of experience.
* If the particular spirit you summoned is unavailable, another may answer your summons instead.
* Lower level spirits are generally more likely to answer a summons from an inexperienced practitioner with less coaxing.
* Absolutely do research and be prepared. Familiarize yourself with the specializations of each spirit and choose the best one for the task. If the spirit who appears is unable to perform the task you requested of them, you may request that they send another in their place.
* And, it is really not advised to summon demons as baby's first magic. You can fuck yourself up and it will take someone who actually knows what they're doing to set things right.