(Didnt bother to read all post)
Heya, I also have a PSP and I can anwser all your questions on how to put Music, Video, pictures on your memory card.
First off I suggest buying a 512 mb memory duo stick. Now get this neato program called PSP Video 9 which can be found here!
http://www.pspvideo9.com/
This program is free and amazing. It allows you to convert video files to PSP format and then it allows you to convert the files via USB cable to your PSP. Just to give you an example of the compressing power this program packs, I recorded a movie called Euro Trip ( 1h 27min, 2.32Gb) and compressed with PSP video 9 using the lowest quality to 168 mb!!!
Music, if you want to put music on your PSP convert the music file to MP3 format, then transfer the music in a folder called "Music" to your PSP's memory stick duo via USB cable.
Photos same as music put the photos in a folder called "Photo" then put it onto your memory stick duo.
I hope that helps all PSP owners and any questions feel free to ask.
http://www.angelfire.com/games5/db_games/