If your not going to do dev on it and all your doing is installing to a live server, then this is what I find to work:
1. Upload the unzipped files of the install package to your web server account.
2. Create an asp.net application on your web host that uses .net 2.0. In future versions of dnn, a minimum of .net 3.5 will be needed. I don't know how your web host setup is, so you have to consult them on how to run asp.net applications.
3. Create the database in sql server. I have found that choosing the express version will run on either the express version or the full versions of sql server. You will either have to do this through your webhost customer service, through a web interface provided by the web host or through sql management studio. Since I don't know your web host setup, I don't know what one to choose for you in the directions.
4. Once the files are uploaded and the database is created, browse to the server/path you uploaded the dnn files to. Example: www.dnnsite.com/.
5. If everything works right, the installer will start. You have at least gotten this far.
6. Choose custom install, then the language you want to use for the installer.
7. Follow the directions in the installer. When it comes to choosing the database/db server, the following things are essential and critical things to note:
A. Username/password. These are given to you by the webhost for the database you are going to use, unless you have the privelages of creating sql server logins yourself. Type them exactly as created. If you use windows logins, leave the sql username/password checkbox unchecked.
B. Database name. Make sure to type it exactly as it was created.
C. Run as DBOwner. Make sure this is checked if the username/password in step A above is the owner of the database. Otherwise uncheck it. The database install will fail if you answer this question wrong.
D. objectQualifier. Make sure you enter one if more than 1 install of dnn lives in the same database. If it doesn't, leave it blank.
8. The rest of the install is pretty simple. The only hard part is getting past the db install. Since it is a community (free) version, the builds you get from codeplex aren't verified builds. This means of course, there could be (or probably are, from what I can see) errors in the builds. Most of them aren't critical, but can be annoying.