First of all, you bought wrong printer :) This "driver" is not in 
production state. It was only an expirement.

So, installation procedures:

1) Open terminal, execute `check-requirements` script, you should see, that
   all required components are correctly installed and available.

2) Install unavailable components

3) Copy `pstoricohddst-gdi` to cups' filters directory (usually
   /usr/lib/cups/filter). 

4) Make sure it is executable by lp user and owned by root:root (i.e.
   chown root:root pstoricohddst-gdi) 

5) Add printer through CUPS' web interface (usually
   http://localhost:631/), click 'Choose file' and select one of provided PPD-files

6) Print!



If you have troubles with printing:

 1) Open terminal, execute `check-requirements` script, copy the output.

 2) Remove all /tmp/pstoricohddst-gdi* directories if found

 3) Enable debug behavior by editing `/usr/lib/cups/filterpstoricohddst-gdi`
    file (line 4)

 4) Re-install printer in cups, make sure printing queue is clear

 5) Send test page

 6) Wait for 60 seconds

 7) In terminal, become root and execute (without pound):
    # grep 'pstoricohddst-gdi' /var/log/*log
    and
    # ls -la /tmp/pstoricohddst-gdi*

 8) Copy whole output of previous commands

 9) Log in to Github (or register if you're unregistered)

10) Open an issue (https://github.com/madlynx/ricoh-sp100/issues/new) with
    problem description, add output of steps 1) and 6)

11) Wait... :) And never ever write me letters through e-mail (I never open
    spam folder, but your mail will arrive there with 146% expectancy)