Aside from FFL, waiting period and cash, what else needed to sell a firearm to someone in CA? Where can I find out which guns can be sold there?

See the link.  These are the only handguns that can be shipped to California.

[url]http://justice.hdcdojnet.state.ca.us/safeguns/safeguns_new.taf[/url]

The roster applies only to new handguns.

"Private party transfers, curio/relic handguns, certain single-action revolvers, and pawn/consignment returns are exempt from this requirement."

IOW you can sell any used handgun to a CA resident as long as it doesn't qualify as an "assault weapon" or one of the other banned types, e.g. guns disguised as something else.

And no hi cap magazine, gotta be 10rd or less.

That only applies to transfers through a dealer where both parties are present.  If the handgun is not on the list, it cannot be shipped to a California dealer for a transfer.

...what else needed to sell a firearm to someone in CA?

Blood, urine and stool samples, a full set of finger and toe prints, skin scrapings, hair sample, retinal scan, voice print, full body CAT scan, you know, the usual stuff for Kalifornication. [x]

Actually, USNJoe, that's not too far off.
After January, a thumbprint is required to go on the DROS.
The legislation for DNA samples is coming later.

OK. So I could buy a non-listed handgun from a police officer [b]BUT[/b]...I know there's a [b]BUT[/b] so tell me what it is.

You can buy a USED, non-listed handgun from [b]anyone[/b] in the state.  The transaction has to be done through an FFL and the gun can't be one that that qualifies as a California "assault weapon", and the transfer cannot include any magazines that hold more than 10 rounds.

If you are asking whether or not it would be legal for you to buy from an LEO a non-listed handgun that he or she bought brand new after The List took effect (1/1/2001), the answer AFAIK is yes.  Could the AG ban such a transaction by regulation?  IMO such a regulation would exceed the AG's authority, but the courts seem to interpret the separation of powers between the executive and legislative branches of the state a lot more loosely than I do.

The biggest "BUT" is that AG Lockyer or his successor can declare anything to be an "assault weapon" at any time in the future.  That problem applies to all new and used firearms.

The gun-ban idiots have ruined one of the states I once truly loved. I would really like to live there now but there's no way I could do that.... I feel for the people who have to endure this legal mess, but please don't give up and let them win forever.

One exception to this is if the gun is willed to you from a deceased family member.

I once imported an evil deadly Colt Woodsman .22 this way, with the DOJ's blessing.