I run a wordpress self-hosted blog and am thinking about switching themes for the first time. I was wondering if switching themes is hard. I know how to download them and click and then it switches, but does it mess everything that I have added in my old theme's coding? For example, I have an adsense ad in between each post. If I switch themes will I have to re-add it? You can see my blog at www.newsnotion.com
If you have a lot of plug ins running it will. You need to install the plug ins that you are using to the new them to get the same effect. At least that is my experience.
If you've hand coded changes to your themes, you will need to re-hand code those changes into your new theme. Plug-ins should work fine without any changes. You can always upload a new theme and try it out. If you don't like the look of things, you can just switch to your old one.