Suggestions on how to build an affiliate system

I am currently working on building a new affiliate system for earlyping.com

Before starting EarlyPing, I had worked in the web hosting industry where I use to talk about my company's affiliate system in various forums related to web hosting, and it did work.

But, I don't have much experience with affiliate system in SaaS.

Since many of you might have already built an affiliate system for SaaS, any suggestions on how to get it done would be really appreciated and helpful.

What sort of affiliate system models seem to work better, where do you target your affiliate system or anything which can help?