GnuCash is financial-accounting software for personal and small business, it's free and licensed under the GNU GPL. Available for GNU/Linux, BSD, Solaris, Mac OS X and Microsoft Windows.
Official Sites and Documentation:
http://www.gnucash.org/
Installation on archlinux:
$sudo pacman -S gnucash
To start application just choose from start menu, or type "gnucash" from terminal. Here's the gnucash welcome start, by default it will show "GNU Cash tip of the day'"
To start using GNU cash, just choose File -> New File, there will be assistant windows to start using GNU Cash. You will setup the currency, add company profile
Just follow the assistance until finish, when you at "Choose accounts to create" there are default default categories to start. In this section maybe you will not need all of these account, so just choose categories that you need.
For this example, i'm choose a simple accounts:
Then forward -> Apply, it's finished. Now you can add your money data into gnucash accounts.
Just add "data" to your accounts. When done. you can create Reports such as : Profit / Loss, General ledger, balance sheet, etc.
For more documentation you can see url below:
http://www.gnucash.org/docs.phtml
Enjoy GNU Cash.
:)