How Many BLOGS Can an Individual Manage ?

I created a BLOG out of curiosity and forgot all about it for a while.
Then I heard about ADSENSE and how one can earn a few cents a day
or more depending on his / her ability to write READABLE stuff.

When I came back to internet, I managed to create a brand new blog
entirely cut-off from my previous blog. Blame it on my ignorance.

Soon, I added another one and now the list stands at seven.
The novice that I was - rather, still am - I have not even compiled
a LIST; I am sure about the figure though because my diary says
"created a blog" on 7 different days in the 3 months gone by.
However, none of my blogs carries any advertisement from ADSENSE
till date, simply because I do not know how to "paste / embed"
the HTML code to my blogs' page/s , let alone positioning the same !!
May I, once again request any kind netizen to
"be my teacher - friend, philosopher or guide " ? I really need it !!
SS
Meanwhile, a QUICK LOOK at the WebSite links below is
HIGHLY RECOMMENDED :
http://www.sanjeevsuri.ws/
http://sanjeevsuri.profitmatic.com/
http://2661.leisureaudiosales.com/