I just started loading BP cartridge myself, here's my process/thoughts. More experienced loaders will hopefully come along.
FFg should work ok. In fact it might be better for experimenting than FFF due to a slower burn resulting in a lower pressure. As antiqueguy said, you want to fill the available space and have mild compression. If you have an air gap with a BP loading; bad mojo. Determine how much volume your case has once your bullet is seated. Remember, Black is measured by volume, not weight.
Although a lube might not be absolutely neccessary, it's an excellent idea for BP loading. Velocity should be low enough that leading shouldn't be a major concern, it can sure help with fouling. Without a lube the fouling is hard and nasty. There's recipes out there for all kinds of concoctions, I finally just mixed 50/50 beeswax and Bore Butter (by weight). Crisco or Vasline should work as well with a beeswax mixture. I've used various thickness lube cookies and they all seemed sufficient.
Prep your case, throw in your charge. I shake mine a bit to settle it before I continue. I then put in a disc of parchment paper (waxed paper should work) to minimize possible powder contamination by the lube cookie. I use a casing as a cutter. Put the lube lube cookie on, top with your bullet and seat. I rely on the lube cookie to provide the amount of compression I desire.
As I said, have just started dabbling with BPCR myself, haven't blown up myself or rifle yet. For cleaning the cases I just throw them in some cold soapy water when I get home then proceed as normal. Seems to work very well.
Hope this helps.