First, depends on what language you want to use in your gallery (you'll be able change it later if you want), select desired language on top right corner.
Then start filling up the fields:
Database server hostname - if you don't know what to input here, you'll need contact your host administrator.
Database name - if "touchofdestiny" is your new database you've created, then enter touchofdestiny
Database username / password - this also you'll need find out from your hoster
Prefix for tables in database - leave it default (or change to whatever you wish, this prefix will be used in names of new fields that the installation process will add into your database)
Admin username / password - enter whatever you want, make sure you remember it, because that is the default administrator account that will be created for you to manage 4images.
After submitting this form 4images will try create config.php file with the data from the form, if it fails, it will offer you download config.php to your computer which then you'll need upload into root of 4images via FTP.
Once config.php is in place and you see 4images homepage, login using administrator username/password that you've submitted during installation process, then you'll see control panel link at the bottom of each page, from there you'll be able manage your 4images.
Hope this helps.