While I have a decent amount of tools, there are certainly tools that would make this easier (a bandsaw could notch the ends with 10% of the work). Again, modify these directions to work best for you.
One last note is if you could get your hands on some old railroad ties, they would work great for this project as well. They'd add a nice green touch while slashing the costs of the project. Unfortunately, I couldn't get my hands on any.
The materials I used are:
11x Pressure treating landscape logs ($4 each at Lowes)
2x 10ft pieces of 3/8" rebar ($4.50 each)
Lots of dirt.
Reciprocating saw (with metal and wood blades)
Drill with 1/2" Spade bit