Click Start.
Click Internet Explorer.
In the address bar type
www.yahoo.com. 
Log in to the e-mail. Type in your username and password.
Click compose to begin your message.
Type the address of the person the e-mail is going to.
Type a message in the e-mail area. I think it is very
important to tell the receiver what the attachment. If you don't tell
them what the attachment is they may not open it.
Click the Attach Files button.
Click the Browse button for file 1.
Now you need to browse and click the file you want to
attach. We are going to attach a picture of a flower. Click My
Documents on the left side of the screen.
Double Click on My Pictures.
Click the picture once.
Click Open. 
The file now appears as file 1.
Click Attach Files. 
Click Continue to message.
Click Send. 