Site design and development – Child themes

Hi everyone,

I would first like to say the new forum layout and site looks good, well done Mark!

Ok. I need some good solid advice and help from everybody.

I have a site which I wish to design and develop. I want a fresh new look and custom design though, one which I will be able to easily update when the time comes, and not have to have the website offline for any reason, once it’s up, if i want to give it a new fresh look down the track, I should be able to do it quite easily.

How do i go about first developing the site, and then design the look of the site, or vice versa?

Do i develop using Child themes, hooks, filters, etc? Do i need to know PHP programming? Is it really hard to code PHP, and what would i need PHP for?
I have a whole heap of items in terms of functionality and ideas which i would like to incorporate and integrate into the website.

Where do i begin, can someone give me a brief run down? I have had a look at some of the tutorials but still, where do i design it, Dreamweaver, or directly on the WordPress/Directory press controls/settings/theme site somehow?

What is the whole process of design and development of the DirectoryPress website broken down into steps?

Thanks so much to anyone who can give me some insight and I will greatly appreciate it!

Stoly