First, make sure you have one of the summon spell selected and have enough mana/energy/whatever to cast it. Then aim fairly close to your feet - most of the conjuration spells don't have a very long range.
The closest you get is a shout which can summon a dragon who has allied with you, this happens during the main quest.
Play the main quest line. At one point you learn the shout to summon a dragon.
you cant look like ezio unless you have skyrim on PC (its a mod)
No you cant
Actually no.
You can it's in the Companions Quests
I don't believe you can summon a skeleton out of thin air like an atronach or familiar, but if there is a dead skeleton, you can use the Raise Zombie or Reanimate Corpse spells, and it will revive and fight for you.
Well you cant necessarily summon them, you have to find them somewhere on each server, check everyday.
A Fusion Summon is considered a special summon, so anything that can respond to a special summon (such as Bottomless Trap Hole) can be used against it.
The headsman armor has no codes, anything.
go to skyrim nexus for mods on pc you cant get mods for xbox
A Ritual Summon is a kind of Special Summon. Anything that affects a Special Summon (such as "Bottomless Trap Hole", "Royal Oppression", etc.) will affect a Ritual Summon.