[where does money to join groups go?]

Dividends are distributed automatically - everyone who can "receive group dividends and pay group liabilities" gets an equal share of L$ paid into a group. I'm not sure how regularly this happens, but whenever I've sold some group-owned land, I usually get my share within a day or so. 

[when I rez an object on my land it just floats about]

If I right click it to Edit it, I can move it into position, but as soon as I deselect it it just floats off. Any ideas?