How many websites one person can possibly handle?

there is no limit.

 

no limit, true. In the past I have personally kept myself totally busy with running just one site. Right now I run about 30+. The result is that I have not enough time to work with any of them hehe. So, it really comes down to what type of sites you are talking about and what's your job in case of all of them. Is it simply the moderation of a user-submitted site? Is it organizing the content? Is it publishing the content? Is it writing the content? And...so on.

 

"I know that it all depends on websites, still how many websites, or how much*traffic*one person can handle without jeopardizing his online ...

 

Everything is always more work than you think it's gonna be. Start with one and get your feet wet, see for yourself, then expand accordingly.

 

This is certainly a matter of personal preference, ability, time and financial resources, etc. Not to mention which approach you take to generate revenue for each site. As WebDev mentioned, if your sites/offers are of a time-consuming service nature then only a couple sites are tolerable. If they are made-for-Adsense sites you can easily handle 100+ by purchasing the articles and handling the simple tasks of set-up (Wordpress installation/configuration, etc) on your own.