I've made a few bows, for the kids - it's hard to find a 10-18lb longbow without having it made for you & our club bowyer has retired due to health problems probably related to making bows.
If you feel the urge to play then the easiest thing to get from a timber merchant is white ash. Telling you how to spot a good piece is another matter & not one I'd feel qualified as an expert on.
The best bit (besides finishing it) is the "artistic" nature of the process - you remove enough, but not too much, wood from the bits that look like they need it so that the limbs work. All by eye & feel. Shame it takes so long, or maybe that's part of the fun
