I want to code a very simple pe executable packer as a learning exercise though I'm not sure how to go about coding this. I understand I will have to use an existing compression library and will have to code a decompression stub within the packed executable. I have done a lot of reading on the pe file format. My previous experience with c++ has been coding small programs. Does anyone have any advice or recommendations on any tutorials I could follow.

Here's one popular library off the top of my head: http://www.7-zip.org/sdk.html

UPX is an open-source and well known library for exactly this purpose:
http://upx.sourceforge.net/