45C: You will only need a few basic items to get started.
A powder flask. A flask that holds 1 ib of powder, is plenty. Lots to choose from. Track of the Wolf is a good source. There are others. You may have a local shop that stocks bp supplies, etc.
An adjustable revolver powder measure: These usually measure anywhere from 10-50 grains, etc.
.45 cal. Lubed felt wads. : Wonder wads, etc. You can also make your own. Very easy to do. (duelist1954 has a couple of good videos on the process).
An alternative, is to place lube directly over the chamber mouths. Very messy, though.
Note: Avoid petroleum based lubes. These do not mix well with bp fouling and create a lot of mess. Stick to beeswax/tallow mixes. Or commercial lube specifically made for bp use.
A capper: The Ted Cash type are a good choice. Or, a simple online capper.
Note: You can skip a capper if you like. Does make the job a lot easier, though.
Balls/bullets: .454" ball is a good choice for your '60 Army. Available from a number of sources. You can also cast your own balls/bullets. Cast from pure lead, is best. Check out: Lee Precision, for options.
Note: .451" and .452" ball will work, too. If that is what you have available. .454" offers the best bore seal, in combination with a felt wad.
BP solvent/lubes, etc.: Ordinary hot, soapy water is one of the best ways to clean bp guns. Ballistol, another good resource. Acts as both a cleaner, and lubricant. Water soluble. Use full strength as a lube. Or dilute, as a cleaner/lube. Ordinary isopropyl alcohol, is also a good cleaner. Removes bore fouling very easily.
Synthetic grease also works well as a lube and protectant. Particularly for internal parts.
BP guns aren't difficult to clean or maintain. Quite easy, once you get the hang of it.
Note: Here's a youtube resource that contains all the detailed information you will need, to load and shoot bp revolvers: duelist1954
The site is an invaluable aid to anyone who shoots bp guns of all kinds.
Host: Mike Beliveau is a noted bp expert, with many years of experience in the field.
Blackie Thomas, also has a good youtube series, on bp revolvers. Including: load info. Useful mods, etc.
capandball: Good resource. Delves into historical significance of bp arms. Also loading info. Cartridge making, etc.
Guns of the West: Good for overall knowledge. Includes load info, cartridge making, etc.
Old Ranger: Another informative source.
Also recommended: Replace factory nipples with SLIX, or Ampco nipples. Far more reliable and reduces cap jams.
A nipple wrench: Nipples will need to be removed, etc., for cylinder cleaning.
Note: It doesn't hurt to put a small dab of anti-seize grease on the nipple threads, when installing in cylinders. Makes them easier to remove
This should cover the basics.