A lot has already been said about expansion and whatnot, so I'll just mention how I managed not to get attacked. By turn 15 I had my starting towns and all the rebel towns including Antwerp under my control.

My princess was married to the English forming a very strong alliance there. Somewhere in the first 5-10 turns, the Danish had sent a princess as an envoy. After reading someone elses guide about keeping your heir un-married until a good offer comes along, I grabbed the Danish princess cementing an alliance with them. That should pretty much take care of those two factions bothering me for quite some time.

That leaves Spain/Portugal/Moor on my South-West front...with HRE and Milan on my South-East and Eastern fronts. With the rebel towns, that gives you easily four castles. I have Tolouse and Bordeux watching the Iberian Penn...and the two castles on the Eastern Front(can't remember their names) keeping an eye on the HRE/Milan.

After I knocked off all the rebels, I worked/am working on my economy. Getting the basic structures up and running, and tuning my castles to either Cav or Archer with regular militia in both. So far, so good...except the Pope is asking me to drop my alliance with the Danish...fat chance of that right now while I am still re-inforcing my towns.

A number of my towns were completely un-defended early, but they were inner towns, and I had alliances set up pretty quickly. It was dicey for a few rounds, but nothing happened.