Alpha Blending w/ DirectDraw

I have a basic game engine all made, scrolling, level loading, basic sprite movement etc etc, and before I move onto anything more importaint I was wondering about alpha blending, lots of games have it to make very nice light effects and other things, and Im totally new to the concept of programming alpha blending and I dont know where to start. :(

You need to use Direct3D for alpha blending (unless I'm mistaken).

 

Hope this helps;

http://msdn.microsoft.com/archive/default.asp?url=/archive/en-us/ddraw7/directdraw7/imover_3ctg.asp