If you write very well, with imaginative prose that can draw the reader in so they can create images in their mind (like a book perhaps) then you may not view images in a blog post as a necessity. The truth however, is that most people who read blogs, need some form of imagery. It breaks the monotony of text and helps visualise things. Even more so if you have a beauty blog, or a food blog, or a travel blog… or any blog really. Except perhaps for money blogs or blogging blogs 😛
You can easily host your images online for free, if you are so inclined. There are benefits to that – if you are on a selfhosted domain, you save space (images take up LOTS of space) and if people steal your images by hotlinking them (which a responsible blogger will NEVER do) you do not suffer unnecessary loss of bandwidth.
You can quite easily host images at sites like Flickr, Photobucket and Imageshack for free. I have done so before this. However, I’m here to plead my case for hosting images on your own blog or server.