General flow question

General flow question

Hi, I've used CRM's for years, but I can't get my head around general flow. 

I have 6 resellers or so, and get quote requests regularly and find deals, leads, quotes etc confusing. 

When someone says, "quote me on 5 blue boxes please, don't know if I need them yet but quote me anyway."

  1. Should I just jump straight into a new quote, save a PDF and send it?
  2. Do I need to worry about entering a deal as well, or starting with a deal?
  3. What about a lead - why do I need a lead - what's it for
  4. Is a lead entered only when someone says "I like your product and let's talk about it further" but isn't at the stage where they want a quote yet?
Hope that makes sense.