Welcome Mesiecat. I am sure Phred's tutorial will help.
The basic thing is: If you just put in an attachment it can only be one per post.
If the pics should be seen directly in the text they need to be on a website before -it does not work directly from your harddisk. A website many people here use for this purpose is www.imagestation.com where many people here have their albums. It's easy and free.

We are looking forward to meet Macaroni and his brothers more often. Filou and Tigris say welcome too.