Line-spacing of the blogs

In style.css :

add

#content P
{
line-height: 0.95em; /**or whatever**/
}

after #content

note that your margins are normal, it looks like that because the letter-spacing (known as kerning)

P, LI, .feedback
{
font: 90%/175% “Lucida Grande”, “Lucida Sans Unicode”, Verdana, sans-serif;
letter-spacing: -1px;
}

Anotehr thing, you have some errors in your stylesheet.

Line 20 :

Delete orphan “{”

Line 61 :

change

color: color:#000000;

to

color:#000000;

Line 356 :

Delete

border-radius: 3px;