I am a K.I.S.S. advocate. Before you get to buying equipment or components, get a copy of The ABCs of Reloading (Edition doesn't matter). The ABCs will show you what reloading is all about, giving the "how to" in a step by step manner, shows the equipment needed, component profiles (powder, primers and bullets. Brass is self exploratory, it's marked on the bottom), and even some cast bullet information.
If you know where to look, all the component info is in every manual I've seen. If you are reloading 38 Special, the 38 Special section will give you the primer used, the powder used, the amount of powder, the bullet (type and size), and the approximate results (yours will vary from the lab results). In the "front half" there are component profiles and give info on each type of component (powder, primer, bullet).
Don't worry about "what bullet" your gun was "designed" for as any modern revolver will safely shoot jacketed, cast, swaged, plated or coated bullets. But for an answer, we need to know what an "older revolver" is. A trip to our local gunsmith will give you the answer as to what bullets you can use.
If you get into reloading, find a load (bullet, powder, primer) in your reloading manual before you buy any components. Begin with the starting load, and don't try to extrapolate charges (many powder charges are not linear, a 5% increase may bring a 25% increase in pressure). Again K.I.S.S.
Reloading is not overly difficult, you just need to follow directions and don't try any "experiments"/loads that are not listed in your manuals.
Go slow. Double check everything. And most important, have fun...