[crxnamja]

There are companies like appsavvy.com who do it for fb games.

I always use agreements. Main things to cover are payment terms and collecting 1/2 of the payment upfront if they are a new advertiser.

Ideally on request is what I send advertisers, otherwise a dashboard is always fun if you have the time to make one.

Raising rates is more about creating competition and value for the advertising available. At the end of the day most advertisers just do the math on the ROI. If they want to stay you can raise rates. More important imo is about retention and having advertisers over the long haul.

Freshbooks.com and other invoices. I just use a google doc template I have and email that to them.