Assuming you're limited to PHB and PHB II, Action Surge is always good for humans. Improved Initiative is also a solid fallback. Weapon Focus is a flat damage bonus. Not too exciting, but solid (scales with tiers, but you don't care about that if you won't hit paragon). Two-Weapon Fighting and Two-Weapon Defense may also be worth considering - after all, you're holding two weapons - a dagger and a staff. Sorcerer implements are fun like that. The former grants a flat damage bonus, like Weapon Focus, the latter gives an AC and Ref bonus.
If PHB 3 (recently came out) is in the running as well, Versatile Expertise can replace Implement Expertise. It basically works only on implements that are also weapons (which daggers are), but it also adds its bonus to weapon attacks, which would be just a melee basic attack in your case. It's not anywhere near necessary (you may not even ever end up caring), it's one of those "might as well, but won't be shooting yourself in the foot if you don't" choices.
