It really is a pain when you type in this long reply and then the forum blanks out when you go to review it.
So I will try to shorten this version:
There are a few things that will make learning the Arduino easier for you:
1) Borrow a book on Arduino from a library to use before you buy one. The book will provide projects for you to do and allow you to become familiar with Arduino and electronics and can often be the shortest route to success compared to learning everything from the Web. Once you finish one book, there are more complicated books available.
2) There are lots of Arduino kits available and many of them have instruction manuals with them. You can build one large project and often, when done you can take it apart and use the components for future projects.
3) Hopefully you have a digital multimeter (dmm). It is the most important tool anybody working with electronics can have. You should not need anything costing more than $60 at this time.
Check out these two pdf's for information on stepper motors:http://www.parallax.com/Portals/0/Downloads/docs/books/sw/Web-SW-v2.1.pdfhttp://www.parallax.com/Portals/0/Downloads/docs/prod/motors/Stepper_Motor_27964.pdf
The first document has information on how to determine which is your power supply connection on pages 154 and 155. The second document has information on how to wire up your unipolar stepper motor using a ULN2003 (a ULN2803 works as well) and example programs. The Javelin Stamp program might be of particular interest to you as it is in Java which is based Java. Java is based on C. Arduino is based on Processing which is based on Java.
As you gain experience with electronics you will become better at reading the specification sheets which provide the important information on the parts you have. Not reading the sheets makes things harder for you. They often have example schematics and programs to show you how to use the part.
The important information about your stepper motor is whether it is unipolar or bipolar, the range of operating voltage, the operating current per coil, and the wiring for each phase. You will need to compare this information to the information provided on the spec sheet for the driver part you buy. The L293D shown in the first pdf works well but, in my opinion, the ULN2x03 looks like it is easier to use.