Oh my! There are entire books written dealing with the questions you're asking! Briefly:
The traditional English longbow is all wood and, when strung, forms a continuous arc from one nock, through the handle, to the other nock. The string does not touch the limbs anywhere except in the nocks. The limbs have a "D" shape in cross section. The handle area is best defined as where the limbs meet. There is no structurally defined handle and the arrow is rested on the knuckle during the draw and shot.
An American longbow has a definite handle section, limbs are laminated wood with fiberglass on the back and belly and are flat in cross section. It also forms the one continuous arc when strung. It has a small shelf on which the arrow rests during the draw and shot.
A western style recurve bow has a pronounced handle section, and usually a much larger shelf for the arrow. Some are designed to be shot with an elevated rest of some type. The limbs are wide and very flat in cross section. The most defining feature of a recurve is the limb profile. Whe strung, the limbs curve back toward the shooter and then the ends re-curve away from the shooter. When drawn, the recurves straighten out somewhat and give the arrow a little extra power when they come back to rest. This is likened to the difference between a good wrist snap when throwing a ball vs keeping the wrist straight. The string contacts the limbs when the bow is at rest.
The Hungarian/Turkish style horse bow recurve is similar in profile to the western recurve, with the ends of the limbs bending forward, away from the shooter. Like the English longbow, there is traditionally no structural handle area. Another point that differs between the this type and the western recurve is the recurve areas of the limbs (the siyahs) are non-working, or 'static'. They are basically levers. Where the western type recurve works through the full limb length, the Hungarian style condenses all that work load into short areas of each limb. It is a highly stressed design.
While the Hungarian style bow can be shot with the typical 3-finger release method with the arrow mounted on the side of the bow closest to the shooter, as is done in most cultures, it is most correctly shot using the Asian method with a thumb release with the arrow mounted on the opposite side of the bow and the arrow resting over the thumb. Here is a step by step pictorial on the shooting method:
http://www.koreanarchery.org/thumbrng.html
Of course, now you can get bows that combine features of one type of bow with features of another type. Hybrids. Semi-longbows, semi-recurves, recurves with longbow handles, longbows with recurve handles. The variety is endless, it seems.
As to which is best for a beginning archer, in my opinion it is the western type recurve. As Talondale says, it would be best to get a lighter draw weight for learning. But I understand that what is best often doesn't match up well with budget and availability. If you absolutely must have a 50 pound minimum draw weight, then so be it. Stay with 50 pounds for now.
Bowtype for a starter?
