Also, if you go to the transport museum, Kelvingrove park is just across the road and is good for a run about on a nice day. It has a busy playpark for the little ones and a skateboard area which might interest older kids. also a duck pond and picnic benches. You can walk up to the university and over the hill to Byres Road where you can have a coffee and do some shopping (kids permitting!)
30 - 40 mins north of glasgow city centre, near stirling, there is a fab safari park. It is called Blair Drummond Safari Park. It is EXCELLENT and would definitely be worth making the trip for. They have a website if you are interested.
I have heard of Blairdrummond although never been myself. We are doing a Monday to Friday trip so not actually there for the weekend. Am going to Oban and Tobermory on Tues/Wed (The Balamory trip has to be done!)
I did think that about the transport musueum and although the boys would probably love it I dont think the girls would share their enthusiasm.
Am staying up near Bellahouston Park in Moss Park - is this anywhere near Tollcross?
Scotland Street School Museum (free) would appeal more to the 8 yrs and 6.5 yrs.
Peoples Palace (free)History of Glasow and its people on Glasgow Green nice cafe in a botanic garden, near to a big park with godd climbing frames and sand pits for all ages.
China Buffet King (all you can eat buffet) Sauchihall St and another location I can't remember the st. My kids love the mini pizzas, mini sausage rolls, carrots, grated chees and prawn crackers, I love the ribs.