I cannot figure out how to load new trimmer line correctly onto the spool and have the bump advance feature work. Any help would be greatly appreciated. Thanks.

Hi,
The obvious question would be to ask if you consulted the manual? If you do not have one, then try:
Poulan Pro - Poulan - Weed Eater - McCulloch - User Manuals
Or:
http://lawnandgarden.manualsonline.com/
And I might add that the Ryobi ones have my favorite discussion. I have taught many a person over the years and "seeing is the best" on that. Cannot co that here. Though YouTube may have one.
Peace,
Clarke

Push the line through the hole in spool. Tie a half hitch in it. Heat knot with some flame to melt a little and relieve it's stress. Trim tail off knot and pull it tight to the spool. Wind the line in the correct direction as noted on the spool. Keep lines Parallel, tight and flat as possible. Each layer should have a slight angle across the former layer. This helps to keep them from slipping between layers and binding. Put 5-6 layers on. Clip line to holder on the spool to hold it tight. Clean post and spool area on the weed eater. Spray it well with WD40 or silicon NOT OIL. Spray spool and line well also. Feed line into hole in spool holder keeping the line taught as you install spool on the post. Make sure line cutter on the guard is sharp with a file. This reduces the line welding when it cuts excess line off.