How do I monitor the performance of my P2Pool instance? Specifically, how can I tell whether I'm finding any shares? It's not clear from the extensive log output. The relevant line seems to be...:

Pool stales: 12% Own: 50±48% Own efficiency: 57±54%


... after about an hour of mining. I'm using poclbm as the miner.

(My hashrate is a mere 30MH/s; I'm just trialling the software until I get a payout - of any size).
p2pool has a higher difficulty, so you won't be submitting many shares, with 30MH/s you will have a greater variance.  p2pool is not the perfect solution for those of us with a low hashrate unfortunately.

The p2pool tells you how many shares you submitted but it's in the lines above the one you pasted, look for where it says Shares: 3 (2 orphan, 0 dead)

Also compare the Pool stales to your own stales.  To have a reliable number, keep p2pool open for at least 24h, but the numbers should be almost the same.  If your own stales percentage is higher than the pool's, you are earning less than you should.  If it is below, you are earning more than you should.