This section shows some of the problems you many encounter and what to look for.
Check that you've added e-bills as a virtual domain to the apache configuration. Also check that the DNS has an entry for e-bills.
If you type nslookup e-bills.yourdomain and get no response then the DNS is not configured properly.
This means that you've not configured the database correctly or built PHP with the database configured properly.
This means that database access is working okay, but you're not entering a valid username/password. Check by running MySQL from the bash prompt that you've entered a username and password for at least one user.
Have you run the scripts to create all of the database tables. Again, if you run MySQL from the bash prompt and enter "show tables;" you should see a list of all of the e-Bills tables.
This implies that LaTeX is not working properly. You can test LaTeX from the bash prompt using one of the test .tex files supplied with the distribution.
It could also be that the paths in the file /home/ebills/bin/ebills_make_pdf do not match those used by your system. Please check this file and edit it as necessary.
A selection of templates are stored in this directory and then the selected one is copied to billformat.tex using the "Configure billing template" menu function. In the future this may result in the template being stored in the database or do something more clever, but for now its simple.
There are a number of areas to check:
Look in /etc/group and in /etc/passwd to check this out.