I got catapulted by a giant the first time too.
I frikkin' love stumbling my way into the Dark Brotherhood like I did.
The courier's note made me rofl hard. I just wanted to humor the kid... Funny to find out they'd honor the contract even from a kid, you just beat them to it.
I just go on insane campaigns across the countryside and come out with phat lewt (or usually more than I can carry in one trip). Raid dweomer places for the metal. I'm level 17 or 18 but me and Lydia are both decked in dweomer armor and weapons and it makes her pretty damn hard to kill because she submits and enemies break off before she's actually in any danger, so unless she's standing in fire or something...
Leading a dragon to somewhere it will land so you can beat on it is probably the only tricky part.
I learned a 'turn ethereal' shout that is probably superior to the invincibility shout someone mentioned in this thread because you can keep beating or casting on a dragon and it lasts long enough for a whole breath attack. I think magical weapons still hit you, but guess what dragons don't count as?
+1 to buying a house just so you can dump your dragon parts in it.