Oh the joys of summoning. Even a small summon (relatively weak) if you aren't careful could cause havoc. An imp that gets away from you could potentially cause more trouble than even 100 pain in the ass pixies that routinely screw with people. Nevermind summoning an upper-echelon demon that makes deals and knows his way around a loophole like a veteran lawyer. (I have a theory about people having their souls ripped out in law school...but that is something for another time. ) You just might wanna stay away from those ones.
Things to remember:
1) you are not the almighty badass of the worlds, you can screw up and there are things bigger than you.
2) start small, don't go trying to summon baal or astaroth your first time out and if you do....kiss your ass goodbye.
3) It is smarter to summon something into a circle..rather than you standing in a circle and it roaming free.
4) there is never something for nothing. Know the terms of any agreements you make with creatures.
As for methods, well, i'll let someone else put that up or i'll update some other time if no one gets around to it.