The American's Guide to Getting Started with UTAU

This is where things can get tricky if you don't speak or understand any Japanese. Luckily, I'm here to help you through this part.

To begin, you can find the program here. You're going to want to click on the link that says "v0.(whatever the latest version number is) zipアーカイブ" This will launch a zipped file which you will unzip to your desired location on your computer.

Now, this should be a fully operational version of UTAU, but it will appear in Japanese. In order for you to get the translated version, you will need to install the English patch which can be found here. Odds are the program won't already have a res folder, so within the utau(whatever the version number is) (ex. utau0276) folder, create a new folder, and name it "res". Then unzip the provided file right into that folder.
Tada! Now you should have a fully functional version of English UTAU! Just double click the exe file and it should be ready to go!

Now, on a side note, I found that if I pulled the UTAU icon out of the folder and tried to launch it, it would run in Japanese. This is because it needs to stay in the folder WITH the translated coding. In order to launch the program in English, you will either need to keep the icon inside the folder, and launch it from there, or you can do what I did and drag the icon down to your dock. (I'm using Windows 7, this may not work for other types) This allows me to have the icon within easy reach at all times, but it still keeps the actual exe file INSIDE of the folder with the translations, therefor allowing the program to run in English.

Downloading UTAU + English Patch