If you're talking about having a range at home, rather than going to a commercial range: I'm too lazy to make a prefab concrete slab for a table, or pour footings.
I've just used three and four cedar or treated 4X4 posts and a sturdy table-top. A sheet of old used 1/2" plywood, cut in half and doubled; glued and screwed together. The key is angle braces from the top of one post to the bottom of another--even old, used 1X4s will do. Use deck paint against weathering; put an old blanket across the top to protect against splinters...Cheap and easy.
Sandbags? Scrounge some of those plastic zipper bags from your friendly local bank...Don't fill them too full. A piece of 4X4 block under the front bag will help with alignment of the rifle, generally...
The actual shooting advice, above, is as good as any!
Have fun, Art
[This message has been edited by Art Eatman (edited April 27, 2000).]