Hello,

I suppose you want to know your mining reward. You should be able to find it in the web interface of your P2pool node reachable through http://YOUR_P2POOL_HOST:9332/.  It should give you statistics about the payout you would get if the P2pool network finds a block now (see under "Payouts if a block were found NOW:"). If you use the default bitcoin address for your payouts, then normally you should find a plot under the link "graphs". If you use a different address it will show 0.
You can also find this information when you go to the web interface of a public node. Normally they should also list the "Payouts if a block were found NOW:". Pick a public node that follows the P2pool share chain you use for mining (jtoomim branch or master branch).
You will only find a quantity different from 0 under "Payouts if a block were found NOW:" if your miners have found at least 1 share in the last 3 days in the share chain.
Also, the "Payouts if a block were found NOW:" quantities are potential payouts. They only become real when the P2pool network finds a block that is accepted in the Bitcoin blockchain. So it may take a while before you get a real payout.

I hope this answers your question. You can find more information on http://p2pool.in/ and http://p2pool.org/.