If you're not using a control panel, then you'd simply create an A entry using * as the entry instead of a name and then setup *.yourdomain.ext in your Apache vhost configuration.
So for your vhost, something such as the following should get you going.
DocumentRoot /path/to/home/folder
...
ServerAlias *.yourdomain.ext
ServerName www.yourdomain.ext
CustomLog domlogs/yourdomain.ext combined
...
The ServerName & ServerAlias are what you want to pay attention to. The ... are just in there for separation and should *not* be added to your vhost configuration.
For your WildCard DNS entry, it should look something like:
*.yourdomain.ext. 14400 IN A 99.99.99.99
- OR -
* 14400 IN A 99.99.99.99
It depends on how your registrar allows you to enter DNS records.
