I've been noticing more questions from people using Wordpress that are new to it, or maybe nervous about messing things up.
Tip #1 - How to not wreck stuff!
Here's a good way to learn without messing things up. Install it more than once!
Even with the smallest plan at Dreamhost, you have a trillion GB of disk space, plus eleventy bazillion TB of bandwidth--so you can afford to spare a little for testing.
Here's what I do.
Create a sub-domain, or even just a new directory, for a test setup. Give it its own database, too.
Install Wordpress in that directory, just like you did with your original setup. Make a few test pages, test posts, test replies, etc... just so you can see your mods in action anywhere they could show up.
Worried about upgrading to a new version? Do it to your test setup first.
Trying a new theme or making your own? Find a new plug-in that looks handy? Try it there first!
When you're sure something works the way it should, do the same thing to your real installation.
This really comes in handy for modifying themes if you're trying to work something into the design, like Adsense or other advertisements, for example.
It's also a good way to test themes/plug-ins that were designed for older versions, to make sure they still work in 2.x version. Some do and some don't, so this is a good way to find out.
Then, I create directories like wp-themes, wp-plugins, etc... in my home directory (/home/username/) and copy the working mods to them.
Then, when I install a new WP site, I can just do something like this from the command line:
cp -r wp-plugins/* domain.com/wp-content/plugins/
That copies all of my known-to-work plugins where they belong, so all I have to do is activate/configure them from the admin section.
Same with the themes:
cp -r wp-themes/* domain.com/wp-content/themes/
Tip #2 - Check for updates from authors!
If you're downloading themes from places like alexking.org (nice theme & style browsers there), or plug-ins from the various sites out there, check the author's home page for updates.
In some cases, the downloads at those places aren't current and some things don't work with version 2.x. Luckily, in most cases, the plug-in/theme authors have updated them to work properly.
I learned this one the hard way, after making a theme work with 2.0... and later finding out that the author beat me to it, but never updated the download sites.
I'll add more as I think of them--and invite others to do the same.
Save $96 at Dreamhost with the 96DOLLARSOFF promo code.