Oooh.
I say start with a knight, since they start with pretty nice armor. First up your strength a few and luck 2-4 (so you get more grass from drops), then focus on Stamina while tossing a few points towards Strength and Vitality here and there. Grab the Dragon Long Sword plus 2 (or it might be plus 1) in the caves in 2-1, and you should be good to go for the rest of the game. Just upgrade that sword, maybe grab some new armor (I'm a fan of he Gloom Armor Yurt wears in 3-2), and focus on your stamina and vitality and you'll be set. You can stick with the shield the knight starts with, but eventually you'll want to grab the Dark Cloud Shield in 2-1 and then trade that for the Dark Silver Shield in 5-3.
I'd also get your intelligence up so that you can equip Total Protection early on (I think it's called Warding in the NA version). That spell essentially covers you in a strong magic armor for a little while, making hits do ~1/3rd their normal dmage. Also get your magic up enough so that you can cast the spell twice before needing to use more magic.
As a Knight, you should be able to beat 1-1 relatively easily, then go on to beat 1-2 at around level 15-17.
Have fun with the game. It's great. It's right up here with LBP as my favorite ps3 game, and nothing else really comes close on the system.
