Serana wrote Hey TTG i was just wondering is conjuration worth it? i mean is it usefull or benefit you in battles and all?

I don't know because I don't use magika. I use basically the warrior and thief skills

Totally depends on what kinda of character you have and how you fight.
I find that summoning with conjuring is pointless, so are the resurrection skills.
They are simple repeats of older spells but lasting a little longer whilst dying around the same number of hits... The ritual stone actually does more than those spells by bringing back larger numbers of allies.

Soul tap is useless due to the obviousness of using soul tap ability weapons.

The only decent skills I find that conjuring have are Bound bow for infinite arrows and Dead thrall to bring back up to 2 un-dead permanent followers.

To get two though you do need to get specific perks... and In a sense if you go all the way like to 100 with conjuring then you can use the forge under the college to get Daedric weapons and armour which is kind of useful.