First of all, the content that you are going to put together is for YOUR website, not anyone else's, it will portray your business, your brand, and your image, so it's important that it's done correctly and in a manner that will work for your online business.
Rule: Never copy and paste content that you have found on the web into your website. This will not do any justice to your business, and in fact your site would be picked up as a duplicate content and those duplicates pages would be taken out of search engines index. Best to avoid this practice if you want your website pages to be easily found by searchers.
Simple steps in putting together content for your website.
Outline: First of all have a clear picture in your mind or on paper of how many pages you need content for such as Home Page, About us Page, Product pages and so forth. By having a clear idea you will be able to analyse the amount of work involved, and also plan accordingly.
Brainstorm: You now have all the pages that you need to write content for, but first, brainstorm the topics that you would like to cover on these pages. Once you have a list of ideas for this page, shortlist the ideas to the most important ones, and the ones that this page cannot do without. Anything that is extra, you do not need.
You now know how many pages you need content for, and what you are going to cover on these pages. Your now ready to write but need to keep below points in mind.
Clear message: Most of the web users don't have much time, well that's how they act, and generally would not read a full page of text, but instead scan though pages, so your message that you are look give out needs to be extremely clear. On a basic web page, you don't want to overdo it with text, if you can use images to portray your message, great stuff, as a picture is worth a thousand words.
Structured: The page needs to be well structured, when your visitors are going through it, they can make sense of things and join paragraphs and points together. Also do not just publish large chunks of text, have them paragraphed nicely with relevant titles, bullet pointed and again use images where possible to go along with the text.
Colours: You can use colours to give out certain messages, use them in titles, or bullet points or even just to highlight a certain text on the page. Make use of colours to make the text of the website more attractive.
Images / Media: When a visitor comes on this page you want them to be interested, and ideally convert them into a lead or a sale for your business. Use images and rich media such as videos to enhance the experience and grab the visitors attention on this page.
Links: Within your text you may mention other areas or pages that you have on your website, such as on your about us page you may mention Contact us or One of your product or service's name. Once you have completed the text for this page, see where you can set relevant hyperlinks. Do not over do the page with hyperlinks, one to three would be sufficient. Also it depends on the size of your website and the page.
Test / Proof: Once you have published your text on the website, you need to test them in various browsers, along with proof checking to ensure it all reads well and makes sense to the general public. Your visitors would be looking at your website from various browsers, and devices, if possible, go through your text in as many browser as possible and also read it on devices such as Smartphone's and tablets. This will give you a better feel of how your visitors would experience this page that you have put together.