If you ask me, save at least 50-70 skill points before you go to chapter 2 to be able to develop one of your offensive spells early. You can't turn into a Mage in chapter 1 anyway. Don't bother with archery, crossbow, sword fighting, axe fighting, staff fighting and dexterity. You won't need them as a magician. Also don't worry about wisdom. It will be raised by book-stands and ancient stone tablets you find during the game, not by LP. Put some points on strength, but not much. Your should somehow raise it at least to 30, ( Strength potions and rings/amulets will help ) so you can use Arik's sword, which is a very good and suitable sword for a magician. Alchemy, pick locks and maybe sneak are important skills and you should learn them. Smithing is needed for two side quest later in the game, but you won't need to learn it at this point. Gut animals and Prospecting ore are worth to have too. I personally didn't find any need for pick pocketing. Seal and create scrolls are necessary for a Mage. Also don't raise mana for now. You will find potions that raise it permanently. They will suffice for a while.
For now, just do quest and get some LP and gold, but try to save them and spend them after you become a magician.