Questions about Yahoo upload and updates

Hi!

This is my first post and I have some general questions about what features I should choose when using wordpress.

I’m loading it up onto yahoo shortly and I wondered if I should be choosing automatic wordpress updates or manual?

I plan on tweeking the templates and the CSS to pretty it up and, add bells and whistles etc… (I guess) I’ll be using the default theme as a starting place.

Will the updates affect my changes? I’m wondering if it wouldn’t be better to do it manually so I have more control?

Also is it better to start with the default theme for purposes of customization?

I’m hoping to get something up that has a similar function as this wordpress blog:
http://update.estrategy.ubc.ca/

B.T.W. I found a new book that seems useful. It covers WordPress, creating a blog from scratch and and setting up a testing environment on your computer:

Blog Design Solutions, by Andy Budd. Friends of Ed. 2006

cheers!