i've played paintball for a couple years and really enjoy it
^what they've been saying, find anything you can, barrels, old cars are cool, make a few bunkers... etc^
paintball is pretty much split into two categories, Woodsball and Speedball
woodsball is usually played in... well..the woods, and may or may not have any human inserted obstacles... there may be woods and fields together. usually the fields for this are larger (2 to 10 acres) because of the large field size stealth and patience play a large role.
speedball is SPEEDY... i've never actually played this but i know it's played on a small field (tiny to 2 acres or so) with plenty of bunkers/barrels/whatever thrown in (set up symmetrically-ish so no side has an advantage). the players start out close to each other with not much room for flanking so the game goes by fast
you might want to cater to either of these styles (if you did woodsball you might throw in trenches and barrels and other things but you wouldn't fill the place with them)
or you might just want to make a style in-between (your own style)
either way, have fun! and good luck!
(you might want to check out this site and it's forum for tactics and stuff
http://www.specialopspaintball.com/ if you register use my ID as the reference 93522
)
[edit] oh, here's another good site
http://www.bansheepaintball.com/tactics.htm
and if you have snake problems, yeah make sure you mow lol... that could be bad especially if you run it as a small business
"We make the worst games in the universe..."