Hi loza.
I'm attending NHS run antenatal classes at my local hospital. I got a leaflet in my pregnancy pack at my 1st appt with midwife. There are all sorts of different classes you can attend but the NHS ones are generally the cheapest and cover the widest range of info. Maybe phone your local hosp women's centre & ask.
In regards to weight-gain; I found a useful tool on:
http://www.fortunebaby.com/pregnancy-weight-ga in-calculator.html (sorry can't figure out how to put a link on)
Its only a guide and its really important that you don't deprive yourself of anything during pregnancy. To give you an idea of weight-gain; I'm 33+5 weeks pg, I weighed 126lbs (9st) pre-preg & now weigh 152lbs (10st12lbs). I'm only 5'2" and everybody is different.