I can help you on this one. Ok first make your flash banner (i perfer in flash professional 8) then save it and export it to get your .swf file then you will need to make your html code. So open up an editor such as notepad and type
<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0" width="820" height="72">
<param name="movie" value="YOURFILE.swf">
<param name="quality" value="high">
<embed src="flash/0464_1.swf" quality="high" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" width="820" height="72"></embed></object>
then save it as a .html and upload the swf and the .html to your webserver and wala