You're really asking two different questions - if you want to do hour-long meetings then the usual way would be to charge a flat rate for that hour of your time, which is what the overwhelming majority of ladies do. If you want to charge per service, how are you going to stick to the one hour time slot? I think 'menu' systems like this are more popular in parlours, but clients generally expect to pay a given amount per hour and have everything included (except for more specialist/rarer services like anal, watersports and so on which often carry an 'extra' charge), rather than have to stop and produce more money every time they decide they might like to do something else.
I would recommend the hourly rate because it is much easier to plan - a client might ask for straight sex at ?X but if he's done some DIY, taken Viagra or had a few drinks, you could be there forever! Also, if someone has booked you for oral but then decides during the meeting he would like full sex as well, are you going to stop and start faffing about with the extra money right in the middle of it all?
Have a read of the main SAAFE page for lots of useful stuff - and like Brandy said, check out the local ladies rates (do a search on Adultwork or use Google to find your local indies). I can't tell you what to do, but I would say that you don't sound particularly keen on the idea and if the most enthusiasm you can muster is being 'willing' to shag them for a maximum of an hour (and don't think you could put up with it for any longer), then I would strongly advise you to consider other options - it is far from being an easy living; if you are not happy it will show in your service and you could ultimately seriously damage your mental health. If you are just nervous about how to get started though - that's what we're here for!