Can you please keep my yahoo icon on my lap top desk top, so i can get my emails ?

SOURCE: email download

I know macs are awesome for the drag and drop, but on firefox on a web based email it is still better to hit "browse" and then find your file that way when attaching to emails.

SOURCE: mail

Hi, just to clarify you are trying to consolidate all of your email to the Mail.app program on your Mac, correct? It's not too tough and I'll let you know a secret. Yahoo normally doesnt allow you to do this without being part of their pay program but they launched "IMAP" support for all free clients. 
The first thing you need to do is open your Mail program (The one on your dock at the bottom of the screen). Then click Mail>Preferences> Then click the + sign in the bottom left hand corner.
Put in your name, your yahoo email account (Example [email protected]) and password. Uncheck Automatically setup my account and click next.
Click the drop down box that says POP and choose IMAP. Replace the info under incoming mail server with imap.next.mail.yahoo.com. Click next.
Check the SSL box and click next again.
Under description put yahoo Replace the information in Outgoing email server with smtp.next.mail.yahoo.com. Put in your email address (remember the @yahoo) and password one more time and click continue. Click continue again, confirm your information and click create.
Your done and your email is good to go.

SOURCE: hard disk icon disappeared from desktop

To add the hard disk icon back onto your desktop, first click the "Finder" button in the dock. It is the dark and light smily face icon at the end of the dock.

Next, click the "Finder" menu item at the top of the screen and then "Preferences". In the "Finder Preferences" window that opens, click the "General" button. From there you can select what system items appear on your desktop. You can click "Hard disks" to re-add the hard disk icon.

SOURCE: hard disk icon has dissapeared from desktop

Try this. Click on the desktop Then from the "Finder" menu choose "Preferences". In the "General" tab, make sure all the boxes are ticked - especially the one for "hard disks".

SOURCE: mail

"Doesn't work" is too vague a symptom to hazard any analysis.
Yes, you can send from Yahoo Mail to Apple Mail. But I'm sure that answer doesn't actually help you in the least.

I suggest you have a voice chat with someone who can help you configure Apple Mail properly.