What are the steps to create Software requirement specifications (SRS)?

OVERVIEW OF THE REQUIREMENTS DEVELOPMENT PROCESS

Identify a set of key end users who collectively have the credibility to define the software that the team is building.
Interview the end users to create a set of preliminary requirements.
Build a simple, interactive User Interface Prototype.
Show the simple User Interface Prototype to the key end users and solicit their feedback. Continue revising the simple prototype, keeping it simple, showing it to the end users, and revising it again until the end users are excited about the software concept.
Develop a style guide that codifies the prototype's look and feel, review it, and put it under change control.
Fully extend the prototype until it demonstrates every functional area of the software. Make the prototype broad enough to cover the whole system, but keep it as shallow as possible. It should demonstrate the functional area, not actually implement it.
Treat the fully extended prototype as the baseline specification. Put it under change control. Then require the developed software to match the prototype exactly except for changes approved through the change control process.
Write the detailed end-user documentation based on the prototype. This detailed end-user documentation will become the detailed software specification, and it should also be put under change control.
Create a separate, non-user-interface requirements document for algorithms, interactions with other hardware and software, and so on. Put that document under change control.