Step 1, read the instructions.
Step 2, dump media in wobbler.
Step 3, dump brass in media.
Step 4, turn wobbler on.
Check after 1 hour, if not clean enough, continue wobbling until brass is clean enough for you.
For me and my brass, I like to keep things simple. I began cleaning brass using walnut shells only (lizzard litter), no additives or car polish. Brass comes out clean and shiny. Today I use http://www.drillspot.com/products/499763/econoline_526020g-40_40_lbs_blast_media, because the pet stores in my small town didn't have any lizzard litter. If you choose to decap prior to cleaning, check the flash hole on each case for stuck media. If you choose to decap after you clean, check brass for media stuck in flash hole (it may be enough to deter or damage decapping pin). I decap after I wobble the brass for no special reason, it just works out that way. I use carbide dies and inspect each case before I put it in the press, both pistol and bottle necked cases, and the bottle necked cases usually need to be lubed, I'll inspect them then. You'll hear folks warn you about scratching dies with dirty cases, but I have never experienced that. I reloaded for mebbe 12 years before I bought a tumbler. I just wiped each case with a mineral spirits dampened cloth while inspecting it.
Cleaning brass is nothing more than a media (walnut shells) rubbing against brass in a machine that keeps the stuff moving and rubbing together, and removing tarnish and rubbing until the brass is clean and shiny. K.I.S.S! You can make it as complicated as you want with mixing media, exotic media (ceramic rods or cones or triangles), solutions before and after tumbling, and additives and polishes added to the media. I just use same common sense I use with all reloading...