Don't worry. It gets better. I have become somewhat of an expert.
I find that with boys it works best to have an activity themed party. We've done rock climbing, laser tag, bowling, paint ball, roller skating. They invite a couple of friends (so it's not too pricey) and I bring a cake and buy pizza.
Most of my mommy friends do the same for their kids. It takes the pressure off having to organize an itinerary of activities to keep them entertained and lots of little boys running around your house can get a little crazy. Especially with a sugar high going on.
Enjoy it- takes pics and make memories for those kids that they can look back at and cherish. That's what birthdays are all about. It really is all about them that day.