We usually buy meat when it's on sale and freeze it. For example, we buy about 6-9 lbs. of hamburger meat (ground chuck, round, etc.) that's solf in about 3 lb packages and repackage it in quart size freezer bags with about 1 lb in each bag. Try to get as much air out of the bag as you can. Having 1 lb bags is great for when we make various recipes because they normally call for 1 or 2 lbs at a time. This will normally last us about a month.
Another thing we do often is purchase a whole pork loin and have it divided (most supermarkets have a butcher that will do this while you wait) up into thin pork chops, thick pork chops, tenderloins, and/or keeping a part whole for a roast. Again once it's home, we divide it up with 2-3 chops/tenderloins per quart sized bag and the roast in a gallon sized bag. Try to get as much air out of the bag as you can. Again we try to use this within 1 or 2 months.
If you're storing for longer than a couple of months, either wrap the meat tightly in foil before placing in the freezer bags or purchase one of those vacuum seal devices that sucks all the air from the bag.
For fish or other seafood, the only recommendation I can give is to buy it pre-frozen. Unless you do a lot of fishing and need to freeze what you catch, buying fresh fish at the store only to freeze it seems silly to me.
This website has more information about freezing meat.
Here's a website that talks about storing vegetables.