"dmg" has got it right.
The SECC and Armadillo are right on the River Clyde and quite close to the city centre. Though not right in the centre, they are walkable - not the most scenic of walks, though the walk along the Clyde is not too bad. There is also a train station quite close to them - just one stop from Central Station, though you have to go down underneath the main station to get to the right platform.
If you can afford to stay at the Crowne Plaza Hotel on the site, there is a covered walkway right from the hotel to the SECC.
Also, from one of the lifts in the Crowne Plaza (the right hand one) you can look down on the Armadillo from above, which is an unusual viewpoint.
I was once in that lift and saw a seaplane approaching to land on the River Clyde (there is a tourist service to Loch Lomond and out to the west coast of Scotland). It is a very odd sensation to be in a building and to look down on a plane landing. Even odder than being in the World Trade Center (as was) and looking down on helicopters flying along the Hudson.