In reply to Carlos236:
As you are a novice, better safe than sorry, and others will say it's easy, which it can be.
Try looking here:
http://www.walkhighlands.co.uk/lochlomond/ben-lomond.shtml
A wee video from the top
http://www.flickr.com/photos/22776031@N05/6533098569/in/set-721576284786453...
Stick to the 'tourist track' (anti clockwise) and come down the same way , avoid the Ptarmagan route which is a little trickier, don't be tempted to follow others down that route.
Take plenty of warm clothes, I have been up a few mountains, and Ben Lomond is my local hill, but I have had some really cold days up there.
The track can get pretty icy, but can be avoided, however the grass to the side can have hidden ice, so on the way down if you don't feel up to crampons, at least take some of those slip over boot anti slip devices. I don't know how sure footed you are, so playing safe.
In case it clags in, always take a map and compass and , know how to use ithem, or at least know what direction you should be heading when ascending/ descending, an be able to set and and follow those bearings.
They now charge for parking ( the bast***s)
If you get here early the hotel has a few spaces right at the front of the loch side, snag is the 4x4 brigade soon take up double the spaces that cars would take up.
If it is an icy morning, watch the road on the way up, it is rarely gritted, that could be the trickiest part of the day, particularly if you have a rear wheel drive car!
I'm sure you will be fine and these are just precautions as I don't know you.