We have 100+ acres planted through one of the forrestry schemes - it's my Dad who deals with it mainly so I'm not as clued up as him
But as Hermit says, they decide what and where the planting is and it is densely planted
You've got a fair bit of maintenance and replanting to do (unless you manage to keep all the rabbits out as well
) and if they're not 100% happy they'll withold payments until YOU bring it up to spec (at your expense)
We've also noticed a definate increased 'wetness' on all surrounding areas that aren't planted, as the rainwater can't penetrate the leaf cover and runs off - so make sure your drainage & ditches are all good
Also, consider carefully what you'll do with the land afterwards - the trees will need to be harvested and it does leave an awful mess. If your ground would be classed as good agricultural land, personally I wouldn't plant it but if it's kinda rough and never going to be good for anything stock wise then go for it. But get them out to see the site and talk to them from there, I've only talked to 3 or 4 forrestry guys, but they were all really helpful.
Good luck whatever you decide !