I started to work freelance just a couple of months ago. My first client asked me to create a web app, to improve his business. I made a little specification about what i was able to do and also an approximation about how long it will take to prepare the application.
We just have some no formal agreement where i told him a deadline when i will present the progress of the project. Also we did not agree any payment at all, since he said to me that he will pay me when the program is live.
What is happening now, is that the program did not meet the deadline and i will present the progress one month after what we agreed. As you see we both made a mistake(myself first), but i hope it is not to late to fix it. I want to make an SLA, to include the amount i want to get paid for my work, and also detailed information about what he will get.
I would appreciate if someone more experienced than me could give me some tips on what should i include in the SLA documment and also if can i get some recommendations for not making the same mistake in the future.