Not tooo sure where this goes but after studying a load of Irish literature and reading Round Ireland With A Fridge I've been totally captivated by the Emerald Isle and plan to travel around Ireland myself sometime soon.
I've never had the opportunity to travel a lot before though so I don't really know how much time I should set aside for the trip itself as well as a rough idea as to how much I'd be spending?
I know this is really vague but I don't know where to start at all with this, feeling pretty lost with it all!
I'm not so good with the money estimates, but I'll try to help you out with time. If you really want to see a good amount of the island, I'd set aside at least 3 weeks, but I'm sure you could easily spend up to at least 6 weeks. If you want a taste, but can't take the time for the whole thing, then a week to two weeks would probably do.
I think you should need around 40 GBP per day and person, maybe a bit less depending upon your style of travel. 3 weeks will be plenty, so you are looking at about 800-900 pounds. A good way to travel in Ireland is with a bicycle and a (very good!) tent. Car and B&B work too as well as a Bus Eireann bus pass and hostels. (Or mix everything.)
Take a map, look at the places you want to go to, look up accomodation prices for the places you are interested in and at the cost it would take you to get from A to B. Add everything together and then allow some money for food and fun things to do.