The first thing to do with the image is to reduce the file size by using a photo edit program such as Arcsoft Photo Studio or Adobe Photo Shop. Once that is done you need a photo host. There are a few of them out there but lets use http/:photobucket.com.
Register and join Photobucket. Open the program and you will see "Browse" Browse your computer and find the image you want to insert into your post. Once you have found it click on "Submit" and allow Photobucket to churn away. If the file is small it wont take long.
Once the process is done you will see three boxes below the image you submitted to your photo album. In those boxes you will see text that looks like the following.
http://img.photobucket.com/albums/v167/ ... arbles.jpg
<img src="http://img.photobucket.com/albums/v167/badpolarbear/marbles.jpg">

Once you have the text you want in your post and want to insert the image you have a couple of options.
1. You can copy the link http://img.photobucket.com/albums/v167/ ... arbles.jpg and paste it into the post and all viewers can click on the link to view the image. This method takes up very little space on the system.
OR
Just copy and paste this link into the post and it will put the picture into the post.

The third method, if you look at the top right of the message body you can see a tag "Img" Click on Img then paste http://img.photobucket.com/albums/v167/ ... arbles.jpg then click on the "Img" tag again and this also will insert the image in the post.
If all else fails Im sure if you submit a post requesting help there would be many members of this forum who would be pleased to help you. I would be one of those people for sure.