I personally use 2 Browsers (FF and Chromium) for those reasons.
FF is my browser to stay private, therefore i am for example constantly not logged into my accounts (google/gmail/youtube).
Additionally:
-) 4 Easy Steps to stop online tracking
https://www.eff.org/deeplinks/2012/04/4-simple-changes-prote...
-) NoScript for FF
Stops every script unless you allow it.
According to http://stallman.org/facebook.html
"Pages that contain Facebook "like" buttons enable Facebook to track visitors to those pages. Facebook tracks the users that see 'like' buttons, even users who never visited facebook.com and never click on those buttons."
There also is a solution described to stop that, but NoScript technically should get rid of the problem.
-) Google has it's own privacy settings, i think you can prevent from being tracked too hard with setting those accordingly
-) DuckDuckGo is getting more and more famous, it's a search engine that market itself as respecting ones privacy and not bubble people (i personally still use google)
http://donttrack.us/
http://dontbubble.us/
-) I also use AdBlock+ so i am not bothered with commercials to annoy me.
-) If you are really paranoid you could use something like Tor/VPN
https://www.torproject.org/
https://torrentfreak.com/which-vpn-providers-really-take-ano...
i personally don't.
-) don't allow third party cookies
-) automatically delete all cookies after shutdown
-) don't use sync programs/functions
-) store data online only strongly encrypted
The reason why i have 2 browsers is, that when i visit an unknown site with lots of multimedia content and when i don't want to be bothered with looking for what script does what (to activate some video embedded on the site for example), then i can just copy it into chromium and it works.
And in chromium i can constantly read e-mails or visit youtube when wanting to leave a comment, in FF i can browse privately (so simultaneously).
If you are sharing your computer with people make sure
-) passwords aren't stored
-) to delete browser/download history in general
That is all i can think of right know.
Oh and e-mail:
-) set up own e-mail server and use encryption
or
-) choose e-mail provider having servers in a country that you trust and that maybe has an encryption feature (for example: Hushmail, located in Canada, free encryption - known to cooperate with us authorities though)
-> if you don't mind paying, CounterMail probably is interesting for you
https://countermail.com/
Update:
Of course, in these days many users just give their information away for free. They react with false assumptions about being tracked (most companies think it is service to their customers - people aren't bothered so much with ads that fit their needs). So if you use facebook and use it to chat with people, you update your status, have many apps on a smartphone and just click on "agree" everytime without being concerned, then you shouldn't be too concerned about being tracked by Google either. Then you are just a hypocrite.