... i heard there were some major changes in magic since last i played(2030), what is it? ...
Well, Sorcery and Summoning have been merged (so you don't have to choose anymore, some spells just happen to summon things) and a lot of spells have been cut. There has also been some severe rebalancing of many spells & effects. I'm sure its all in the manual as well, but if you want a quick rundown of (what I have found to be) the powerful ones:
Air II - Maelstrom: New stackbuster now that Meteor Storm is gone. Max damage = 50%, doesn't hit allies/neutrals.
Death I-III: Skeletons are still in, and the level two and three spells are summons with death mana affinity, so if you are going death magic, go all out.
Sun III - Summon Aurealis: Summon with 2 sun affinity, making it extremely powerful if you have several sun nodes.
Shadow III - Summon mistform: Hidden Nationality summon that can pilliage
Metamagic II - Dispel Magic: In addition to its previous effect, it also reverts improved mana nodes back to their raw form, making the tower of mastery fairly easy to build.
Of course there are many opinions on this and I fully expect to get flamed because I didn't include someones favorite, but this should be enough to get you started. Experiment and have fun!