Most likely you'll be in Balloch which is at the head of the loch from there or from Tarbet you can get a cruise up the loch.
have a look at this website
http://www.stirling.co.uk/trossachs/waterfalls.htm Inversnaid picnic area has some nice views across the loch.
Google is your friend also check out the Visit Scotland website
You could also visit Luss which is where they filmed the TV series Take the High Road