The Demons of Hell were often the Gods of antiquity.
The lineage of a particular Demon is the subject of scholarly research. Needless to say, it can be very confusing.
Asmodeus, the Demon of Lust, is a particular favorite with Satanic bisexual and gay men for obvious reasons.
Working with Demons is essentially the same as working with Satan.
1. You invite the Demon to the ritual.
2. Offer some form of reciprocity by way of Sacrifice for the help you ask of Him.
3. You invite Him to leave.
Whereas culturally we are all aware of Satan, the Demons are less well known.
So if you are considering working with a Demon, it is worth getting to know Him well before you start, otherwise your ritual may be ineffective.
Demons have the advantage of having specialist skills and powers that you may wish to recruit to your ritual workings. But they can be difficult to control, and therefore probably best avoided altogether by the beginner.