Putting together your website content is an important aspect of content writing and Information Architecture Design.
Study your direct competition and the industry leaders. You can do this inside and outside your local area which can be helpful even if you only cater to your local market because you might find good ideas that your direct competition doesn't even know about.
Making a spreadsheet of your competition can be very useful because you can rate the usability of your competitors websites on a scale of 1 to 5 and refer back to the best ones when you begin outlining the pages on your website. If you want, you can also rate the design of your competitors and set a goal to achieve a certain level of quality for your graphic design. It's good to know where you stand and make your website goals based of this information.
You can research dozens or even hundreds of competitors. The more the better. You might also want to go back and spend a little extra time studying the sites that you gave a higher rating.
After you have a confident understanding of what everybody else in your industry is doing, both good and bad, it is time to start making your list of potential pages on your site. For organization purposes, it is a good idea to make this list on a new page in the same spreadsheet that has your research information. Your list should include everything that you can put on a website. This can be extremely helpful in knowing what to avoid when writing your website content. Knowing is half the battle and it's better to make educated decisions than rely on guess-work.
This should certainly be done after you do your research. You will want to keep your brainstorm list and your research data readily available because they will come in handy with this step. It's a good idea to keep this information consolidated in the same spreadsheet, if possible.
Simply copy and paste items from your brainstorm list onto your page outline. Be sure to group your information into appropriate categories. For instance, you should put all of your services pages in the same category and label it "services." A good website navigation will have 5-7 main categories with relevant sub-categories under each main one.
Doing graphic design on a website without knowing the pages is like flying blind. It's just not a good idea because you don't know where you are going.