First off, ignore the help files that come with it. They have never helped me, not even once. A lot of the help file is geared toward the command-line interface that people in industry might use, not the graphical editors that you normally use. Your best bets for help are Google, and asking around on this board.
**broken link removed**
that's what got me started making parts.
I sometimes copy from other packages, but often make my own from scratch, as it's not really any harder.
The trick to making the PCB layout portion of a part is to make sure you set your grid to the right dimensions so the pins wind up in the right places, and the key to making the schematic symbol for a part is to make sure that you set the grid the SAME as you use for actually drawing schematics. Typically that's 0.1 inch. You can change the grid to get more intricate part symbols but make sure that the contact points of the pins end up on the grid crossings, otherwise when you go to hook a wire to it on a 0.1" grid in your schematic, it's not going to line up. That was something that took me a while to figure out, as stupid as it may sound.