Free unzipping: Download FreeZip from FreeZip homepage or SuperZip from ZDNet or StuffIt Expander for Macintosh from Aladdin Systems, Inc.
Free image viewing and printing: Download IrfanView from Irfan's Homepage or Lview from ZDNet.
More free software at The Free Site's Free Software Section and at the excellent ZDNet website.
Disclaimer: I have not personally tested StuffIt Expander for Macintosh. Not repsonsible for any misperformance or lack of performance of any of the above software.