Right. Peace reigns.
I know the SGH is building a new maternity unit - not sure if it's open yet. If so, this info may be out of date (my youngest is 13 months old). When I was there, there was one birthing pool, but you were only allowed to use it for labouring in, not to give birth (it's because the midwives didn't have the right training). And it was only available on a first come first served basis, so you could get lucky or not. I wasn't allowed to use it when ds1 was on his way because they broke my waters and they thought there was some blood or something in the amniotic fluid. I ended up with a crash cs, and so when ds2 came along, they had me all wired up and I couldn't use it then either. hey ho. But the room looked nice: definitely nicer than the other labour rooms.
If you really want a water birth, you might consider switching to Paisley, where I'm pretty sure you can give birth in the pool.
The antenatal classes I attended were organised by the ante-natal unit I attended (Millbrae) and were not all that useful - but you do get a tour of the labour ward, which was quite useful, because we knew where to go once it arrived (and inevitably it will be the middle of the night!). The parentcraft stuff at the SGH may be ante-natal - not sure, but they defiitely do post0natal stuff there. We went when ds1 was about 5 weeks old and I was struggling to establish bf (failed in the end . If this happens to you though, with the benefit of hindsight (and MN!), I'd go to the QMH, where the bf help is apparently brilliant - some of the others on here (Weeonion, Tallulah) have used it and can tell you more.
My only other tip is TAKE FOOD -the SGH food is ghastly, and DP was dispatched to M&S at Braehead to bring me nice things to eat.
Do ask away if there's anything else.
And welcome !