- I took alchemy for the enchanting potions so you can upgrade your robes even more.
Alchemy is necessary to maximize the quality of crafted Armor and Weapons, but a Mage who's just enchanting his own cloth really doesn't need it. Simply getting Enchanting to 100 with the proper 8 perks will give you the ability to enchant Fortify Destruction (-25%). Put that on your Head, Neck, Chest, and Ring, and you're casting your Destruction spells for free. You can get that up to -29% with Alchemy, but you obviously can't reduce the casting cost of spells beyond 100%. You could get two schools down to -87%, and a third down to -58%, but that's kinda overkill. Just shoot for free Destruction and Illusion casting, and completely fill out the Alteration tree.
- So illusion is kind of like sneak? He would love something like invisibility i told him that you cannot use it in the game only enemies can... didn't know you could also. So in illusion you can go invisible and be harder to detect and can kill people in a stealthy manner?
Once you've got the Invisibility spell, you can only be detected by sound. A Muffled enchant on your boots on the Muffled Movement perk in Sneak takes care of that.
- How do you get dectruction and Illusion spells for free?
100 Enchanting skill, 5/5 Enchanter, 1/1 Insightful Enchanter, 1/1 Corpus Enchanter, Grand Soul gems filled with Grand Souls, and Fortify Destruction and Fortify Illusion effects already learned. Enchant those effects on a hood, robe, necklace, and ring. Voila.
So basically destruction = combat tree used to blow stuff up
alteration = defensive tree to buff you up and make you more resistant
conjuration / illusion = crowd control. One summons minnions the other uses spells to cc
Restoration = defensive but it heals you instead of giving you more buffs.
That's basically right. Alteration does a lot of stuff (Paralyze, Detect Life, Light spells, etc.) as well as defense. Illusion is crowd control and Invisibility. In Resto you're only taking Novice Restoration, Regeneration (+50% to heals) and Necromage (a nice damage boost against undead). He will need to heal himself occasionally.