Are tracking cookies really so dangerous?

I want to know what is so bad about tracking cookies. I don’t think they’re so bad, other than that some of them may be good enough to actually track passwords. But I don’t care if they know my IP address, I don’t care if they know want websites I go to, I don’t care if they use info to give me ads. In fact, the latter one I welcome; means I’ll get ads that I care about.

I just need to know if there is something very bad about them that I do not know about, because I had into a problem. So my plan was to use Friefox with Adblock Plus and No Scrip in a reverse way. For Adblock I was going have it turned off (because websites make money from you seeing those advertisements and I want to respect that.) but use it to block big annoying ads that slow down my computer or are just plain disturbing. The great thing about this is that it will only block that one ad, and not the ad provider, so it works.

For No scrip I was going have it on, bet lets all the websites I trust go through. No the idea was to allow all the advertisers EXCEPT for the ones that give tracking cookies such as Doubleclick, Right Media, Adrevolver, and so on. Now there is the part that makes me want to give up, I love Google; I use their toolbar, their search engine, their email, a lot of things. But Google has some sort of partnership with Doubleclick or something, even though I have itself Doubleclick blocked I am still get their tracking cookies from Google and the only way to stop it is to block Google itself.

Should I really block Google just to escape one brand of tracking cookie? I don’t mind the collecting info about me to make money off of, I don’t care if they know what websites I go to, and I will only care if they get important secret information from such as passwords. (But I don’t even have a bank account or a credit card that I use over the Internet, just passwords.)

Sorry for any bad grammar I might have or if this is in the wrong place.

if you cant control cookies from within your browser or third party software, you can opt-out from some of the more 'famous' cookies by setting a 'opt-out' cookie. See link:
http://www.worldprivacyforum.org/cookieoptout.html

You should clear cookies after using a public computer to delete possible log on passwords etc. And of course never use a public computer for personal/financial information.