Write your own blog posts from your original ideas. Instead of copying a post from somewhere else, create your own unique posts. If the writing is your original work, then you hold the copyright.
Upload photos that you take yourself. If you have taken a photograph, then you hold the copyright to it. However, if you take a photo from somewhere else online, then you might be violating someone else's copyright to the photo. Many sites online offer pictures that you can use for free or for a small free or attribution. You can search for works in the creative commons using special search engines. Other sites where you can find pictures to use include Flickr, Wikimedia and Fotopedia. Be sure to read the conditions for each image's use.
Quote small portions of other people's work and attribute it to them. Fair use is a defense to copyright infringement. It is an admission that you infringed the copyright, but your infringement should be allowed. Quoting small portions of another person's work is generally considered fair use as long as you attribute the work to the creator.
Read the copyright information on the sites from which you take content. Some people allow you to use their work under certain circumstances. You will often find those circumstances on their Web pages. If you do not see anything, then you cannot use the work without prior permission.