Some Blogger blogs, this one among them, have user pics in comments enabled. This means that, if you have an image stored on your Blogger profile, that image will show on your comments on the Blogger comments page. User pics do *not* show next to comments on the individual pages for each thread.
Blogger does not allow you to upload images directly to your profile. Instead, you must provide a URL of up to 86 characters. The image must be in .png, .gif, or .jpeg format. If you have a graphics program such as Paint Shop Pro or Photoshop, you can simply "open" an image with the .jpg extension and "save as," giving the file the .jpeg extension. Then, upload it to your online storage area, free web space, or whatever, and enter the URL in the blank on the profile form. Click the orenge save button at the bottom of the form to save your changes.
As to the uploading itself, you have a choice. If your ISP provides free web space, as many do, you can upload your images to that space for storage. To use this option, you'll need an FTP program to transfer the image files to your webspace.
A simpler, less expensive alternative is the Hello software system, offered free to Blogger members. According to the info on the Hello page, this system is fully integrated with Blogger and will allow you to upload images to your Blogger blogs with minimal effort or knowledge of the particulars. This system may also allow you to create a URL accessible to the Blogger profile.
You can upload images on the fly to your post threads by means of the "add Image" function on the post creation screen. This function permits you to upload images directly from your computer.