When writing a basic End User License Agreement, be sure to at least:
clearly identify yourself/your business;
clear state the rules for user behaviour and access to your product/software;
disclose the copyright/intellectual property license that applies (e.g. open source);
include other details of the software license including conditions for termination;
include any disclaimers and limitation of liability statements.
You can see how this all comes together in the EULA example text below.