Probably best link to recommend for a read before you buy an unsuitable cut is:
http://www.bbc.co.uk/food/get_cooking/cooks_gu ide/lamb.shtml
Also, treat it simply - don't get all cheffy and try over-complicated recipes - and definitely go for the best quality meat you can afford - go to a butcher for advice, they will enjoy you asking for ideas, or to your local farmers' market, and definitely not the meat counter in a supermarket - some of their produce may be satisfactory, but there are better sources.
Best advice re the cooking is to let the meat stand before carving - you should always do this in any case as it lets the juices settle and the flavour will be a lot better.
You can get a gravy ready while the meat is standing, and prep up the veg without getting all flustered about timings - nice new potatoes and sugar snap peas, or oven roast some fresh carrots in orange juice and a little honey (takes 30 mins in a casserole dish) is a nice addition.
Hope this helps..and bon appetit!