To make a blog on your new website or not depends entirely on your project purposes. If you imagine your new web resource as an organic whole, it will be easier. What role the blog will perform depends not only on how often you will publish content, but also on your desire to blog. Because the blog needs to be updated regularly, you have to answer on every single comment, advise and review. If you will not answer, users will have the impression that you can ignore their interest and they can just stop commenting. Besides you need to check comments for flood, spam or advertising as well. You can set up pre-moderation, but it will still take a lot of time. I firmly believe that it's better to have a well-designed project without any blog than to have unremarkable web resource with a blog. If you ready to manage with it, you're an open-minded person and you always have something useful to say, of course, your blog on the website is an awesome opportunity to make a good tutorial or whatever content. When you blog will be a well-known your website will improve its rating, besides there are more opportunities like offers from different advertisers to test their services and sites, and then publish a review in the blog and you will have loyalty and trust which are the best marketing tools. Who knows maybe you will become a new influencer!