For those asking about books, there are 3 that I know were released physically.
Fantasy Craft - the core book with everything you need. The PDF that's readily available is the 2nd printing, which is the same as the first with some errata. If you want physical, that's harder to find, and you'll either want the 2nd printing or the 1st printing w/ the errata document.
Here is a page of free Fantasy Craft downloads including the aforementioned errata, free NPC builder software, and a few other goodies.
Adventure Companion - 3 ready-to-use settings(nothing as detailed as a dedicated Forgotten Realms book, but a nice starter), a few new classes at each tier(basic, expert, master), and some new feats and a handful of new campaign qualities. All very well thought out.
Time of High Adventure - It's just 3 adventures with some NPC and monster stats thrown in as needed. No new player options IIRC. 2 of the adventures are published separately in their own PDFs(to avoid accidental double-purchase, in case you're interested in this kind of things).
Then there are the
Call to Arms PDFs. They're just new classes. Some of them are included in the Adventure Companion. Avatar, Crusader, Inquisitor, Shinobi, Skirmisher, and Witch Hunter are not, in case you want to know which you can get without doing an accidental double purchase.
Laboratory of the Forsaken - another adventure, only available in PDF.
Then there's the big, unreleased thing . . .
Spellbound - at least, I think this is what it was going to be called. They've given the option to refund your preorder since it's been quite a few years, but I keep holding out hope that it'll come out someday so have thus far not done that. That's probably dumb of me, but I really, really want it and don't want to give up. (This is also why I'll never, ever, EVER buy a Mistborn RPG product even though I love Sanderson's work to death.) Anyway, it's the big magic supplement. New spells; newer, less generic magic-using classes. I know at some point they released what they already had, but for the life of me I can't find the PDF on this computer. Sorry, if I could, I'd give you more specific info about what they actually finished.
Next in the pipeline was supposed to be an equipment and gear book. I don't even know if they had a tentative name for it. But since it looks less and less likely that a full release of Spellbound will ever see the light of day, this one's even more of a pipe dream.