Deliver Touch Spells
If the master is 3rd level or higher, a familiar can deliver touch spells for him. If the master and the familiar are in contact at the time the master casts a touch spell, he can designate his familiar as the “toucher.” The familiar can then deliver the touch spell just as the master could. As usual, if the master casts another spell before the touch is delivered, the touch spell dissipates.
There are various spells that have a touch range; spells of both offensive and defensive natures fall into this category. Try not to mix melee range touch spells with spells that require ranged touch attacks, like ray spells; your familiar can only deliver range:touch spells and not rays. Normally, this doesn't seem to be a very good thing to do, but there are two basic perks that all familiars that serve a master of 3rd level or higher can do: helping his master with MAD (Multiple Attribute Dependency) and action economy.
Multiple Attribute Dependency: Melee touch attacks are melee attacks, which means that you get to add your strength modifier to your attack roll; since the strength attribute is a dump stat for a wizard, getting a familiar that has a lot better strength modifier than you is going to help a lot getting those offensive touch spells through. However, beefy familiars with high strength ratings, although they exist, they are not always what you are looking for; familiars with the Weapon Finesse feat and really high dexterity ratings are more common that you'd think and some of the best familiars already have both. Although this benefit is the most obvious one, do note that it only matters with offensive spells, since you're going to cast defensive spells on your teammates, anyway.
Action Economy: Since your familiar is the 'toucher', he gets to deliver your spell; normally, when casting range:touch spells, assuming that you don't want to hold the charge, you have to select a target when you finish the spell. Now, assume that you're in a position that you don't want to move near your enemies, so you move the spell to your familiar and it holds the charge until its turn - then on its turn, it moves and attacks with the spell, so you're both safe and not spending that move and standard action. Holding the charge is also a very good option if you want to have quick buffs on the first round of battle - you cast a touch range spell and let your familiar to hold the charge indefinitely, until you get into trouble; then it touches you, releasing the spell energy and you're free to act normally. Of course, this method has its flaws (if you cast any other spell, the touch spell dissipates), but there are some workarounds.
Metaspells to be used with the 'Deliver Touch Spells' ability
Spectral Hand is a oftenly used wizard spell, in order to deliver your touch spells from a distance. Its level is very low - just second level, so you can use the previously used methods to transfer some of your spells to your familiar easily. Now your familiar can deliver the touch spells that you assign it to with his spectral hand, so not only you can benefit from your familiar's statistics (assuming it has or it somehow gets Weapon Finesse), but you're getting a +2 bonus on top of that. Moreover your familiar doesn't have to get in danger by closing in to an enemy! Perhaps the greatest benefit of all is, again, the main point of sharing your spells with your familiar: action economy; you get to deliver your touch spells safely, with a good attack roll buff and most of all, you don't have to spend an action casting that Spectral Hand, someone else does it for you!
If you're thinking of buffing your familiar with a Persistent spell, look no further - Spell Flower should be your top choice if you're using this feature extensively. Now, normally you can't cast spells while you're holding the charge, because the first spell will dissipate; not the case with Spell Flower, though! You get to hold one charge per limb, which may prove to be awesome with some familiars that have additional extremities. So, buff your companion with a Persistent Spell Flower, get it to hold the charge on multiple of your favorite touch spells (buff or not, it doesn't matter) and have it use them the first round of combat; the best part is that since the spells do not dissipate, you're free to cast spells as you wish.