I have been to Belgium, but i flew.
(Eurostar is too much of a hassle when you're starting your journey in Scotland!)
You'll like it... fab people, beer and chocolate.
I stayed in Vilvoorde, just outside of Brussels, and it was a lovely wee town with a nice old church. Everyone from hotel desk clerk to taxi drivers were fab. When i asked about a kettle for my room, they went out to the shop and bought me one!