I downloaded a bunch of stuff from the freebies section and now here i sit, looking at my pot-o-gold, not knowing which folders each go into. So without complicating things too much, I need to know which folders to put these things into...

.mat files?

premade objects like glassware or buildings..?

textures?

terrains?

cloud presets and sky atmospheres?

.rdb files? what are they and where do they go?

water presets?

stand alone things like planets..?

fantfile shows a really cool fantasy background. dunno what it is but it was downloaded a lot from the site. i think i really want this one but i need to research how to use it because it is 10mb in size.

EEEEK. i know this is probabally annoying to you guys because everyone here makes gorgeous stuff and i'm all new new new... and i'm kinda intimidated about asking but i have to start SOMEWHERE, right?
thanks
Laura