tbh without a lot more info on the woodland its difficult to give any advice, what tree species, what size timber, whats the topography like, whats the soils like, is it in any grant schemes, do you have felling licenses, has the woodland been well managed in the past etc etc.
I work doing woodland advice and consultancy and i looked at a block of 30acres earlier in the week that the people though they could make some income off but the timber is all firewood quality and its pretty thin anyway. I have advised them to try and get some grant funding on the woodland to help cover the costs of the felling, and to get themselves a quadbike and timber trailer also with some funding if possible. So they can get some out as and when but to be honest its only going to be maybe 10days per winters work for them felling and then maybe a month processing by hand, unless they hire a processor in. 25acres isnt going to keep you that busy for long really, if you were just doing odd days then that would be fine, but I have to say i agree with Rupe to an extent at getting the kit to get the timber out would probably eat significantly into your profits as would buying processing equipment. I know this isnt what many people want to hear when they seek advise on their woodlands but its the sad reality of woodland ownership. Getting the timber out with the landrover isnt really a long term solution either you will quickly get a bad back and fed up of loading and unloading it especially if your cutting every thing into rings in the woods.
The other options are dependant on species is looking at adding value to the products so above and beyond firewood, if you have timber you could convert into fencing products, either cleft or milled? local furniture makers if you have a few better quality oaks for example can yield a far higher income than the firewood will. Rustic furniture making along side the firewood so you could sell some at local shows etc. (I wont suggest charcoal as its a lot of work and selling it can be an issue unless you have an outlet that wants a regular known supply)
Anyway hopefully this isnt to negative and its given you some food for thought.