The diaries section allows you the reader to experience a blog-within-the-blog.  For example let's say I have not posted an in depth look at the Celtics point guards on the main page.  You can get the ball rolling with a diary.  To give you a better idea here's a good example of a diary entry from Blog-a-Bull .  

Try and post something of substance, a paragraph or longer, while saving shorter ventures for the comment section of my posts.  Also particularly good diaries may make the leap to the front page. Finally, be respectful of everyone and enjoy.  

I'll end this with an awesome phone conversation from the summer of 1985:

"This is Bill Walton of the Los Angeles Clippers. I would like to play for your team. I think I can help." - Bill Walton

"It's Bill Walton. He wants to come here." - Red Auerbach .

"Got get him." - Larry Bird.

- I've got goosebumps.