No official rules for handling PC resurrections. It's only happened on two occasions (that I know of; I'm not following all the current adventures). In Closed Eye, the players didn't want to be resurrected. In Dextyr and the Strikers, they were automatically raised as a plot device. In other words, it hasn't come up yet.
I think in general, it should be up to the DM to handle it in a way appropriate to the adventure. If it makes sense for the other PCs to grab the body and arrange to have it raised, I'd probably handle it that way by preference, most of the time. If it's not appropriate, e.g. TPK, or the other PCs have to run, I'd try to arrange for NPCs to recover the body after the danger has passed, take it to someplace appropriate (e.g. Temple of Lauto, if you're in Daunton. Local witch-doctor, if you're out in the wilds), have them Speak With Dead to find out if the PCs want to be raised and are willing to pay the cost, and do it.
I can imagine situations where it just wouldn't be possible to recover the body, e.g. if you're fighting on the edge of a volcano and get pushed in. If that happens, well, too bad, I guess.