Congratulations on making a new server... here's some resources you may want to read....
[Tutorial] Server Rules, the right way (awesome tutorial on setting and sticking to rules)
Paypal, Money, and Minecraft Servers (good overview on how to get players pay and not get bitten by PayPal or Google Checkout)
Common Answers / FAQ (from the official MCF, so a good read)
/r/admincraft (Reddit... for MC admins)
As for your issue... well, you shouldn't be editing that file directly unless you can't access the command line/terminal/console for some reason. You should almost always use /op <player-name> and remove op's using /deop <player-name>. If you edit the file you will need to reload it which, with most server software, means restarting the server. Best recommendation is to blank out the file (delete everything... heck, delete the file), restart the server, then use command line/terminal/console to op yourself...
If you don't have access to command line/terminal/console (but for some reason have access to the files?!), you may need to do some hunting.
