Remon,
If you have the full version of Adobe Acrobat 5.0, you can scan sheet music directly to that program. Simply choose Acrobat as the program you wish to send the scan to.
For example, using the HP ScanJet scanning utility, choose Acrobat 5.0 from the drop-down list of programs, and click "scan". After the scan is complete, Acrobat will open with the page as you scanned it. You can then edit it a little and save it with whatever name you choose. If the music you are scanning is longer than one page,simoply save the first page as described above. Then, return to your scanning utility and scan the next page. Save that page. Then open your original file and click on "Insert Pages" in the document menu. Find the next page's file and open it.
That's all there is to it, but you must have the full version of Acrobat. You can't do any of this with only the free Acrobat Reader.