Upgrading Drupal

Sorry, this is my first core update, so I'm really worried I'll mess something up in a big way.
I'm using 7.26 on a Dreamhost account, and I have already installed a lot of modules and set up the page.
It's not live yet, but I would hate for all this to go to waste. The manual install seems like there's a lot of things that can go wrong.
Drush seems easier, but I haven't used command lines since 1997 and am not familliar with Unix shells.

What manner of updating would you recommend?
How can I be sure nothing will go wrong?

Hello all:

I've recently tried to get back into developing Drupal sites after a brief hiatus but I keep having the same issue with trying to manually update Drupal Core past the 7.22 that I was able to install automatically via my GoDaddy hosting.

Updated my site from 7.26 to 7.27. I can no longer run Cron, flush caches - nothing - or link to any page - what am I missing?
Thanks,
-Bill

HI

I need help.
I'm upgrading my site from D5 to D7.
Upgrade from D5 to D6 was ok.
Upgrading from D6 to D7 I lost all attouched files in my news.

Before to run update script I can read:

Hello Drupal Community!

I am wondering how I can update my core drupal 7 index file to the latest 7 version. The problem apparently is my index 7 file got broken after I tried to update one of my modules. I asked my site administrator to do a back up restore but it did not fix the problem and I can't access my site. Can anyone give me some advice about what to do next? I am thinking I need to update my drupal 7 core but how can I do that when I can no longer access my site?