Here's how I handle the blitz, sometimes it works, sometimes not. This is all just my opinion, and there are others more qualified to answer, but anyway...
-First things first, it helps to pick a team with a good O line. If your O line gets obliterated in a 4 man rush, you've got no chance to pick up the blitz. So pick a good team.
- It is absolutely vital that you recognize the blitz immediately after the snap. You need to know which player(s) is coming, it makes a difference on how you handle it. When you snap the ball, don't look at your receivers, look at the linebackers. You can learn 80% of what you need to know about a defense by what the LBs do, they are excellent indicators. Almost all blitzes come from the LBs, and even if they don't blitz, their behavior will tell you if the defense is man coverage or zone coverage. You should practice your plays enough to know what receivers are likely to be open against both types of defense. If it's zone coverage, try to throw into windows in the defense. If it's man, it's all about finding single coverage and keeping the ball away from the safeties. When you call a play, you should be able to say "if it's man, look at receiver A, if it's zone hit receiver B, and receiver X is my safety valve in case of the blitz".
- You need to realize that blitzes are a gamble. When a team blitzes, there is a vacancy where the blitzing LB or CB came from and an opportunity for the offense. Throw to the vacancy. The LB's pass coverage responsibility was probably either to cover the TE or a RB out of the back field. When the LB blitzes, this responsibility usually transfers to one of the safeties. This means two things. First, that receiver is going to be open until the safety can close the gap. If you hit him quickly you probably have an easy 5-10 yards. Secondly, and more interestingly, because the safety is in coming up to cover short, there is no over-the-top help for the CB on his side. If you have any time to at all, throw the fly route to this side, you're guarrenteed single coverage and the receiver has the advantage in that situation.
- Roll away from the blitz. Granted it helps to have a mobile QB, but even if you don't rolling will give you a precious extra second to let routes develop, and it naturally aids you in directional passing, so you'll have less of those floaters off of your back foot.
-Make them respect the run. If they are blitzing up the middle all the time, run a couple of toss plays. If they are spreading the D linemen out, run a few dives. Make the defense play honest. You'll be very easy to shut down if you become predictable and one dimensional. Even if you're only averaging 2 yards a carry, keep pounding it. 3rd and 6 ain't half bad, much better than giving up 2 long sacks on 1st and 2nd down because you've become predictable.