Hi Sam, It's nice to see you asking so many questions, your enthusiasm is contagious.
Here is a link on food rewards:
http://www.artofnaturaldressage.com/forum/viewtopic.php?f=27&t=932You will figure out how it will work best for you and your horse. With Morgan he likes verbal commands and can be encouraged by voice to try higher/ more/ longer by voice praise whilst waiting a little longer for the click and treat! I only use this after he we have a relieble cue and behaviour in place.
Some horses get frustrated with the speed at which you feed the treats/others are overly excited and then calm down etc. You will have to gauge what works best for you. Oviously each day is a new day with different energy from both of you, so I mostly go with the flow of what Morgan wants to offer and then ask for other things.
The whole idea is no pressure. If you are working in an enclosed area, your horse still can't really walk off and will come back for want of anything else to do.........if you can walk out to the paddock and your horse chooses to come over and play then you know they want to, not because they think they have to.
I hope that helps a little.
I see Romy just posted.....but I will add this anyway.......