Nice to see another Keogh Moodling.
1. Set up an external web page editor to create the course web pages (I'd prefer to use one I am familiar with - NVU).
2. Where the web pages should be stored for Moodle to use them.
Answers to both of the above depend on another question. Do you wish to store the pages in the moodle database, or in the moodle filestore? And do you wish those pages to make use of Moodle's stylesheets?
If you create a web page in moodle, using the moodle editor (either in wysiwyg or source-code mode) the html thus created is stored in the database, and combined with templates and the stylesheets to create the pages that are actually displayed in moodle. This is what happens if you tell moodle to create a web page resource.
Another way to display web pages in moodle is to create them elsewhere (you could use Nvu, or dreamweaver, or any other editor), take the directory structure thus created (including any images and so on), zip it up, upload the zip to the files area of the moodle course you are working on, and then unzip within moodle (moodle has this unzipping function built-in).
You can then create a resource in a moodle course that points to the index page for these html pages, and have the pages displayed either in a pop-up window, or in a frame.
3. Where other items for the course, pictures, videos etc., should be stored.
These are stored in the files area of the course that you are working on, and then referenced by creating moodle resources that point to them.
4. How to get these web pages to become part of the course including navigating from one page to the next.
Adda resource to the course - make it a file or weblink resource - point it to the location of the index files for your html pages.
If you are uploading html pages to the files area, then you simply need to include relative links in each page and then you can navigate - moodle isn't involved in this at all, except in providing the frame or pop-up window to display the pages in. If you have created the pages within moodle then to navigate to the next one you would need to know the URL of the next resource (hover your mouse over the name of the resource in the course in order to find this out).
Alternatively you could make use of the Lesson module, which allows you to build up linked collections f pages, with branches, and questions in between to control which direction a learner goes in. The third-part book module is also a good and simple way to display multiple html pages.
5. How to set up video streaming.
Moodle itself is not a streaming server, but the new flash-based media player provided by the moodle multimedia filter can stream mpg, mov, wmv and other formats to individuals, and all they need is a web browser with the flash plugin.
I'd suggest that if you haven't already been there, http://docs.moodle.org/ would be a good place to visit - some careful phrasing of searches could find most of the information that you need.
Sean M Keogh