Additional to what Matt replied, you can make great use of your blog to answer such questions. It'd help not only build trust but also convert the readers into possible customers. Depending upon the quality and value, you may even receive natural hares and backlinks without asking.

If you're talking about content, then it may come into any form (images, graphics, videos) as long as it serves your site visitors' purpose and add value. Just take care of unique value proposition, focused page and relevancy.

Homepage can have no content at all to 300 words minimum. Note that search engines would rank you on the basis of alt tag, title tag and H tags too if done properly. All you need to answer is

Who you are

What you do

How your visitor is benefited

These 3 questions can be answered with any form of content.

The category page can have a 50-100 words precise and clean description of category using engaging words and style. make great use of H and alt tags.

Product page can have 100-500 words depending upon what you are selling and how much words it need to convince your visitor with value. May be features, how it works, tips etc.

On product pages, user generated reviews may add an extra edge in terms of content and credibility.

Hope this helps.