One main difference between English and Western riding, besides the saddles, is the way you hold the reins. A lot of western horses are neck-reined, while in English, neck-reining is never used, as far as I know.
Is your horse trained in English? Because if not, she may be confused when you start using two hands with her.
I would strongly suggest starting English on a reliable, well-trained English horse, and with an instructor to help you, if possible. It's MUCH easier to learn with someone right there with you, leading you step by step, rather than reading someone's advice on the internet.
But... that being said, I'll give you some pointers anyway, just to start you out. Once you have the saddle and bridle on your horse (you'll also need an English bridle), make sure the stirrup length is right for you. To check this, put the iron under your arm, at your armpit, and stretch the leather all the way down your arm, closing your fist under the flap. If its the same length as your arm, then its a good length. If not, raise the buckle up or down to change it. Make sure its even on both sides. To check to see if its even, have the leathers hang down on both sides and look at the horse straight on from the front. You'll be able to tell if the irons fall evenly on both sides.
Mounting is basically the same, except you don't have a horn to hold onto. Simply hold onto the pommel (the front of the saddle) with your left hand, and the cantle (back of saddle) with your right. Always make sure your cinch (in English called girth) is tight enough. Reins are held in two hands, not spread far apart but together, with the fingers like this: http://www.dkimages.com/discover/pre...2/90022944.JPG
Unlike western, reins are usually not long and loose. There should be a line from your elbow, down your arm to the horse's mouth. Here is an example of an English position: http://www.equine-world.co.uk/riding...s/position.jpg
Notice how the line from heel to shoulder to head. This is ideally what you want.
I can't get into a ton of detail, but here's the basics for stop & go for English riding.
go/walk = usually a click and squeeze with lower leg
stop = "whoa" (I use "ho" sometimes too), sitting back with the body, and a slight tug with reins
trot = click and squeeze with lower leg and heel, if necessary
turn to right = squeeze of right leg followed by slight tug (I hate that
word, but its all I can think of for now) with right rein
turn to left = squeeze with left leg followed by left rein
- heels down, toes pointing forward, like you said
- to make sure your leg position is correct, stand straight up in the stirrups and slowly sink back into the saddle; your legs shouldn't move, the way they fall into place is where they should naturally go
- don't have a tight rein! (sooo many riders ride only with their hands ... use your seat and legs -- get an instructor to help you with this)
Well, that's all I can think of for now, but good luck and please ask if any of this didn't make sense!