I saw lots of scripts with 1000's of files in it,,,,, and inside each files there are lots of functions,,,,,, so, to code a big site, it is necessary to plan first,,,,, how you will plan to write a script ? do u use any softwares to draw flowcharts, or any algorithms,,, i have started with PHP and interested to know these,,,,,
no need to think of whole site. Try to make it in blocks. Like first registration, then cookie management etc.
architecture and code organization is important. most php development is done as per modular programming and hence each logical functionality is divided into functions to make good reuse of them.. if i am to plan a big project, i would do something like this: 1. List out features / components of project 2. Make list of things to do in each component. 3. Prioritize which module to make first. 4. Begin a modular programming (started OOP recently) and keep code as clean as possible. For GUI, you can embed output of different functions into html code as and when required, however i would recommend to keep embedding only till variable display and not keeping whole bunch of lines or loop inside html.
its always good to draw diagrams to understand flow and integration points, specially for big projects where many programmers are at times involved and several integration points are available amongst components..
It all completely depends on the website you are trying to create. If you are looking for a website that has to do with thousands of users, with customization per user and everything else then I wouldn't be surprised if you had tons of files. However, if you're trying to create a website that will only have a few pages with information on it, expect a few folders, pages or such. Planning does great things.