for these requests. A client can formulate a request form quite easily. I receive lots of these forms from clients who want sites designed and to be honest I don't think I've ever had two the same.
What's very important is to lay out your requirements in as much detail as possible. If you can do it, attach a draft site navigation guide , so that everyone who quotes is doing so on a level playing field as far as the number of pages or sections is concerned.
I like to develop sites with the client - in a private directory on my own server space - so that clients are involved in the design process as it goes along. This saves time and effort for both parties, and I suggest that you ensure that your form contains a request for a 'time to develop' estimate. Many client/designer disputes occur as a result of misunderstandings about development timescales, and it's worth dealing with that aspect right at the start.
If you need more specific input come back to your thread and ask - otherwise I'll waffle on for ever.