Personally, I wouldn't get too attached to any one method of stabilizing your rifle. It is worth your while to learn how to shoot with different techniques, and you'll become a better marksman if you make the effort to try a few things!
If you are merely trying to make a poor-man's benchrest, then the sandbag idea is a fine one. As someone else said, you can put two sandbags up front, and a bag or "sand sock" in the rear to stabilize the firearm (you can also tuck your weak arm back to stabilize the stock of the rifle, in lieu of a rear rest). The idea here is to keep the rifle steady without relying on your own ability to do so (or at the very least, relying less on your ability to do so).
As for practical field shooting, the sling approach is definitely something you should try to master. A properly used shooting sling will make you more stable in just about any position (whether you are standing, kneeling, or shooting prone). You can also use natural rests to stabilize your gun in the field (sides of trees, rocks, etc).
Personally, I rarely shoot from a benchrest these days. If I am going for my most accurate groups, I'll usually just setup some sandbags and shoot from a prone position. A bipod will also work well for this purpose, but I've never bothered to add one to a .22lr!
Honestly, you picked a great rifle to learn on, at least in my opinion. Even with today's inflated ammo prices, you can shoot a .22LR all day without breaking the bank (500 rds for approximately $15-20). So, you'll be able to play around with your new toy to see what works well for you, as well as what does not.
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