You can learn a lot of little helpful tidbits by listening to what Googles head of webspam has to say, and lucky for webmasters, he's always saying through various channels on the web. This includes YouTube videos, his blog, Google+, Twitter, Google's official blogs and various forums and comments threads.
In case you wondering, according to Cutts (talking on Twitter), it's fine if you want to send a link to a Google Docs spreadsheet when you report Penguin spam.
Last week, Cutts tweeted that Google had read and processed almost all post-Penguin spam reports:
@Penguin_Spam yup yup, we've read/processed almost all of them. A few recent ones left.
I'm sure there have been some reports submitted since then, but clearly Google isn't taking too long to sift through them.