Again, study. The symbols are used with a particular system. If that is the one you want to follow, then start at the beginning. Learnung about thw goetic system will teach you its intricacies, and how those sigils are meant to be used. It is a very old system, so its books should be available online, distributed as public domain material.
Many systems will put a person through a very long learning phase before allowing them to take the first step into summoning. There are some good reasons. The first is to solidify a person's ability to concentrate. Another is that with the belief of summoning, banishing must be a very well-learned skill in order to clear the space, or send away anything unruly or unwanted.
If you have never tried summoning, I don't suggest starting with demons. Be sure you read and study as much as you can. NOTHING wants to be summoned just so you can see if it works. Ask yourself these questions:
What am I summoning?
Why and I summoning it?
and
What do I do if something goes wrong?
Don't put your cart before your horse. STUDY STUDY STUDY! It'll pay off in the end.
DemonZareh, what are you talking about? That sounds like something right out of the World of Darkness games.
While most things you could summon do want a price for their services nothing would be able to physically shove it's nails into you to make you bleed. You might be physically tired afterward, that happens sometimes. It may ask for an offering of blood, but that's on you if and how you draw it.
It would depend on the type of spirit you intend on summoning. Guardian spirits, deceased family and protective spirits can be summoned with minimal fuss. However I wouldn't summon a random spirit or demon (Or fey for that matter) without some serious study with people who have been doing that for years. The more years the better as then they can tell you what to avoid.
Also, make sure you summon something you can send away, too. Nothing worse that summoning a spirit that ends up haunting you in the end. **cringes**
From what I have Gathered about Solomon's Goetia, I know two things for certain. 1) It is a very very very old system of magic and is thus incredible complicated. Learning it will require all of your attention and focus. 2) Those "demons" of Solomon are most definitely not to be trifled with, as ANY negative actions taken against or with one is likely to backfire several times over in your psyche (think the Law of Threes). A practitioner once ascribed working with them to pulling the pin out of a live grenade and praying you have the ability to put it back when you're done.
If you intend on pursuing this particular branch of magick, please be VERY careful.