What do small business people do with regards to 'legal' when selling software [closed]

Question

For those who have sold software successfully over the Internet, after going to the effort of writing the software, creating a website, get a domain name, hosting the website, setting up a merchant facility, creating a trial version, etc - what do you do about the legal aspect of allowing the version downloaded from the Internet to be used only within the intended scope. That is from the perspective of say:-

• each workstation, or server, or CPU, etc counts as a CAL
• Development Vs Evaluation Vs Production
• support and upgrades
• not allowing the user to on-sell
• disallow modifying/extending

Is there a standard procedure / contract for this - i.e. are there documents in the public domain for this or can I take one from another software vendor, tailor it, etc. Or, do I need to hand crank it - i.e. get an accountant/legal-person to write it up