Anyone help please? I'm lookin on the forums and I cant decide...
Also, should I use a shield and 1handed sword because I can get extra defence?
And what bout dex knights?

As a Knight you'll go 2h weapons because of the damage output, and because you need them for your skills. With the amount of defnce you get naturally from your armor and for being a knight, you won't need a shield.

AoE Build:
Str: XX
Stam: 100-110

Go for Stam first, once you get it to about the 100-110 area go for Str. You can add Str ealier, but Stamina is going to be your major stat so focus on that. Don't even think about touching Dex or Int, they are totally not needed at all for Knight.

Leveling 15-65: Skill spam Splmash and Keenwheel, it's a pain in the ass and boring but unles you're willing to cough up the money to pay for restat for an AoE build, it your only choice.

65-90: AoE. Should be pretty easy, just grab a RM go to the desired spawn, gather and kill. Use a 2h Axe, it has the better AoE, it stuns and hits all enemies around you. The sword one only hits enemies in front of you.

90-105: 1v1, optional. Requires a lot of money to get good equip, and to be honest is not worth it all until you're at this level. I'm level 82 and went Dex, I've realized I could've been leveling faster if I just stuck to AoE a little longer.

Most go 1v1 because of the horrible spawns, but it's all a matter of preference.

1v1: You'll still need a RM, and good equipment. Knights have a good selection of green sets and weapons to choose from. I myself chose the Recorn set and the H. Ambi Axe. I do decent dmg and hit 92% attack speed with haste.

But there's a lot of different combinations.

Build: The best one since you'll need a RM anyways
Str: xx
Stam: 15
Dex: 15
Int: 15

Easy, your natural defense will protect you, and buffs will keep you going.

105+: Up to you, but with the V7 set, AoEing has been made easier.

This is a very helpful and much more in depth guide (http://flyffworld.com/forums/showthread.php?t=17940)

By the way, this is all from personal experience, I may not be 100% correct and your opinions may differ. But this is what I've found to be true.