I responded recently to a similar request and I will copy below what i said. The Scottish Canals web site is well worth a look. I note that you wish to cruise from Glasgow to Edinburgh but I think all the hire boats are based in Falkirk at the Wheel.
This is what I said
Sorry not to have responded sooner but I was a wee bit busy when I first saw the message. (thanks, Ange and Brian for reminding me :-) )
The Lowland canals in Scotland are very quiet and peaceful with some lovely scenery. Capercaillie Cruisers ( http://www.capercailliecruisers.co.uk/ ) at Falkirk are agents for the main hire companies up here and all the trips start at the Wheel - an amazing structure and being on it on a boat is an experience not to be missed. As Ange said, going east on the Union canal, to Edinburgh and back can be accomplished well within a week. On the way you pass through Linlithgow, ( http://www.linlithgow.com/ ) a place well worth exploring. On the way to Linlithgow you get great views down the Firth of Forth to the Forth road and rail bridges. Another good stopping place (for food) is at Ratho where you will find the Bridge Inn canal side. Between Ratho and Edinburgh you cross the Scott Russell aqueduct over the city bypass before going through Wester Hailes where the canal had to be completely rebuilt before it could be reopened. At the canal terminus in Edinburgh Quay you are a short walk for the city centre with all it has to offer.
Returning to Falkirk, go back down the Wheel and turn right and you will descend a flight of broad locks which will take you down to the Helix project with the amazing kelpies ( http://www.thehelix.co.uk/ ) . These are almost complete and we look forward to their official opening (a new bit of canal to the River Forth) next April. Coming back up the locks go past the Wheel and continue to Glasgow where again you can moor very near the city centre. Unlike the Union canal into Edinburgh, the Forth and Clyde canal is a broad deeper canal and it is mainly used by sea going boats crossing from one side of Scotland to the other. After Glasgow, there is a flight of locks down to Bowling where the canal joins the Firth of Clyde and if you have time, it is worth going down there. On the way you go through Clydebank where there is a boat through chip shop! You stop at the rear window and give your order, just like MacDonalds do for cars.
The Wheel and all the locks and lift bridges are done for you by Scottish Canals staff and while this makes it a more restful trip, it means that you have to keep to their time table.
With two weeks you should be able to visit all the canal termini - Edinburgh, Helix, Glasgow and Bowling, but it will depend on how much time you wish to spend exploring off the canal.
I may be just a wee bit biased, having a little Sea Otter up here and having attended all the events since the canals reopened, but I think the Lowland canals are well worth a visit.
If you want any more information about specific aspects, please ask
haggis