What headset is it? You should look at the headset's website for installation instructions and/or exploded diagrams. In my experience with 4-5 different frames, it's not the frame brand that is important, it's the headset brand.... but that said, they're all virtually the same with just minor differernces.
Or, just look at some diagrams for a few different manufacturers (i.e. FSA, Cane Creek) until you see one that makes sense for the parts you have or until you understand the general way the go together, in which case I think your particular headset will make sense.
Cartridge bearings, loose or caged? Same basic principles for both, just minor differences.
Maybe you could post a picture of everything you have? If you have already done that, I apologize, but I can't see it. I'll bet with a photo of all the parts you have, one of us can give you exact directions.
Also a couple of confusing things: the top cap is the coin-shaped thing above the stem with the bolt in it that tightens the headset. The cone spacer is the, cone shaped spacer that is just above the frame's head tube. Sometimes it's pretty short (~5mm), sometimes it's fairly tall (~20 mm). I get confused when people refer to that as the headset top cap, because it isn't. Like any other spacer, it simply transfers compression pressure from the top cap/stem down onto the headset bearings. The bottom of the cone spacer is usually designed to impart the pressure directly onto the top cartridge bearing, or onto the compression ring which inserts into the top bearing (cartridge or loose/caged balls).
If you have a rubber O ring, the ones that I've seen fit into a recess inside the cone spacer, causing a seal between the cone spacer and the fork's steer tube. Usually they don't come as a separate part, but are intalled in the cone spacer. So look there to see if yours is like that. There may be another location for it though, thus the need to find out what headset it is, and look at the exploded diagram... or post a photo of what you have.
The compression ring I referred to: There's sometimes, but not always a thin metal or plastic ring that slides over the steer tube, directly onto the top bearing, inserting into the top bearing inner bevel, or against the inner surface of loose or caged balls. It is usually called a compression ring, not a seal. But I really don't know what parts you or others are referring to - a photo of EVERY part you have (including the crown race!) would probably make this very simple.
There's usually nothing that sits between the lower bearing and the crown race or between it and the frame head tube's lower bearing seat. It just goes: crown race - lower bearing - lower head tube bearing seat, if that makes sense.