Ask them about the risk of uterine rupture vs the risk from c.section surgery (my consultant was very clear that the risks are very similar, so this made it easier to say ' in that case I want to try for VBAC')
Ask what type of room/conditions you will be able to labour in - I was not allowed the 'birth centre', and was promised a room on the 'non high risk' labour/delivery side, but, when I turned up in active labour, the midwives stuck me on the 'high risk' side (less access to useful things like birthing balls, light dimmers - but I had packed the car full of stuff I might find useful including birthing ball, extra pillow, tens machine) - It's worthwhile visiting the rooms before hand so you can think about what might make it less clinical and more relaxing for you.
Something that i wished I had made more of a fuss of was, if, at some point, you decide you would rather have another section, will they listen to you.
My first birth (which ended in emergency section) was extremely long, painful( epidural didn't work), and traumatic. I had no intention of having a similar second birth, but def. wanted to attempt VBAC. I wrote in my birth plan, if labour is not progessing please c-section, and, if pain relief does not work sufficiently please c-section.....but when the time came, and after many hours and exactly the same complications that I had with the first birth, I had asked and asked for a section and been ignored....I had a VBAC, but delivered in an operating theatre whilst being prepped for another emergency section, after another immensely long, painful labour.
Def. ask about whether they will induce if you go past term, and if they will allow syntocin(?) drip if your labour is slow..(I would expect 'no's ' to these, but at least you will know).
And check on just how much monitoring of the baby they will want (although IME it depends on the midwive, I had one who was very nervous and anxious about 'what the doctor will think if there's a gap in the trace', which meant I could not be as active as I wanted without her stressing about it.
Good luck - the recovery after a VBAC is so much quicker than a section, I'd choose it again, for that reason alone!