I was having trouble installing Geeknote on my Mint system, but was able to fix it. Based on this experience, here are the steps to properly install Geeknote (tested on the specs given in this post's subject:
$ sudo apt-get install libboost-dev g++ html2text python-sqlalchemy libmarkdown2 git
# Download the repository.
$ git clone git://github.com/VitaliyRodnenko/geeknote.git
$ cd geeknote
$ sudo python setup.py install
# Launch Geeknote and go through login procedure.
$ geeknote login
Let me know if this works for you!