Please help me in learning how to do this.

You must first get an online photo storage account. There are several free sites like Photobucket (this is the one most folks use). Once you have that setup you must uplosd your photos to your account. Once there, there will be several lines of "code" that allow you to share the photos. The code that begins with [img] and ends with [/img] is the one you need to post here. When you see that IMG code you can copy and paste it to the post where you want it to appear.