There's loads of stuff to do, both around the Witches Trail and further afield, depending on fitness and skill. Yes it's hilly, rocky and sometimes technical but it is a stunning place to ride, if you get decent weather. One word of warning is to take plenty of midge repellant. Avon Skin so Soft (the green one only) is particularly good although I also use 100% DEET, just to make sure!
The Witches Trail is first class and has got to be on your list. It's very flexible so you can pick and choose how much you want to do and maps are available on line and at the gondola station. You can miss out parts of the main climb if you wanted. There's a skills section round the back of the gondola which is good for a bit of practice before you go for the main trails. I can thoroughly recommend the farm shop cafe at the Auction Mart for food instead of the ski centre. We had lovely home made soup, bread and cakes with a very nice view of the Ben. There is an off road path to it from the ski centre that is used for the 10 under the ben events but I think it's better as a post ride reward.
If you're feeling particularly fit, you could do part of the West Highland Way- get the first train from Fort William to Tyndrum or Crianlarrich (sp?) in the morning and follow the WHW back to Fort William. Monster climbs and descents, especially over the Devil's Staircase, but an immense feeling of satisfaction when you finish. I think it's about 80 miles and took us all day but that included stops at various points for food.
The Great Glen is nice for cycling although I haven't done much of it myself.
Laggan Wolftrax is about 40 mins drive from Fort William and has recently been expanded. There are now two red sections, the one I have ridden is not terribly hard but is good fun, a black (to be avoided unless you like your drops big and your rocks very pointy) and a final swoopy blue section taking you back down to the cafe at the bottom. The climb here is not too bad and they have fitted a lot in to a small space.There is a long section of board walk which is unavoidable. It's quite wide although has a couple of corners that freak me out sometimes as the landing could be painful.
There are a couple of books with good ride suggestions in them- one by Kenny Wilson and a Bike Scotland book.
http://www.mountainbikescotland.com/index.html
http://www.amazon.co.uk/Bike-Scotland-Trails-Guide-Mountain/dp/0955454808/ref=pd_bxgy_b_img_b/026-3008182-5029260
Kenny's routes usually are a bit more of a challenge as he is not averse to a bit of bike carrying but they are worth it for the sheer feeling of remoteness. You are unlikely to see another cyclist, or another person for that matter, all day. Can't say that about your local trail centre!
There's a Scottish Cross Country race on the 27th July so worth avoiding the Witches trail that day. The course will be marked out on the Saturday but available to ride on.
I've been to Fort William loads and always enjoy it. You'll have a blast!
