Word of advice to the OP: You should pre-calculate the attack bonuses and damage for every power you have. This helps to prevent confusion as well as speed up combat because you won't be recalculating everything each time you attack.
As for the question about the character sheets, there's two sections dealing with attacks. There's the attack and damage workspace, and then the list of basic attacks underneath that. You can use the attack and damage workspaces to calculate out your two most common attacks. The basic attack list is more for just listing your different attacks for reference. I usually use the second section to list the stat versus defense type (ie- STR vs AC, or STR vs FORT, etc...), but you could just as easily use your Attack Bonus versus Defense type.
I've attached a pretty cool PDF that you can print out and use. It's a sheet that you can use to list all of your powers and calculate your various bonuses. It works really great for keeping everything straight and making it easy to reference.
One final note though. You only add your proficiency bonus to attacks with the "Weapon" keyword. This means that if you're using a weapon as an implement (like a Swordmage), then you don't add the proficiency bonus. Additionally, there are certain non-weapon attacks (The Fighter's Shield Bash, for example) that don't add the proficiency bonus either. These will usually either have a bonus to hit (like Shield Bash) or they will target a non-AC defense (like the Swordmage does). So, make sure that you watch your keywords when calculating your attack bonus.
