If you haven’t been affected by Penguin yet then the best thing is to make sure you won’t be, before its too late. For a lot of people though it is too late and everyday that a penalty remains or the filter affects your ranking you are losing money so you need a quick penguin recovery if possible
There are actually two potential issues resulting from Penguin and they need to be dealt with in different ways. One is that the algorithm may simply not favor you as much any more: many people have commented on the fact that authority sites have benefitted a lot from the Penguin update and the most recent Panda update.
For other webmasters though they will have actually received a penalty and need to get that lifted as soon as possible in order to commence your Penguin recovery plan.
Some people have started talking about whether it is worth dumping penalized sites and starting again. For some certainly Penguin recovery is going to be a tough up hill battle; only in extreme circumstances when you have nothing but bad links that Google either now ignore or penalize you for and when you have little quality or valuable content should you give up on a site.
First things first you should sign up for Google Webmaster tools if you haven’t already, if you have then sign in and see if there is anything from Google, they should have e-mailed notification of giving you penalties for bad links but you may have missed them.
If you are unsure whether you have a penalty or not check, if you don’t then you may actually have more hard work to do though your penguin recovery may be quicker.
If you have been penalized after the penguin update then you probably have one or more links from a bad neighborhood, Penguin has greatly expanded what Google considers a bad neighborhood now and it includes a lot of private blogging networks and authority link networks: even where you’re not penalized they are being de-indexed and you may lose the rank you have built up.
Private blog networks shouldn’t be confused with general blogging sites where you have added valuable and relevant content and other sites where you submit good quality content by the way. Private Blog Networks are mainly paid for services like My Article Network and Build My Rank: you now need to cut your losses and remove these links to your site if you can if you have them.
For a complete Penguin Recovery you may have to wait but you can tell Google if you think you shouldn’t have been affected by a penalty or the filter and tell them once you have taken the actions they have recommended to you.
If you haven’t had a penalty but have just seen rankings drop it is still a good idea to remove links from private blog networks for your website’s penguin recovery to start apace.
For those who haven’t done their own SEO but have got others to do it hopefully you should know what they did and where your links are from if not use Google’s webmaster tools to check.
As well as removing these poor quality links you may want to look at the quality of your site’s content. This includes making sure it is well written and flows well but also that your keyword density is low, a couple of mentions should be enough and it certainly shouldn’t be higher than 1%; consider removing old content with few inward links that was written at a time when writing SEO content was very different.