Unlike English, Japanese language is basically consisting of the sound of letters called "Hiragana". If you learn the "Hiragana", you are somewhat able to read books or articles with "Furigana", a "Hiragana-support" for the learners, even though you can not understand the context. However, many English speakers find difficulty of learning individual "Hiragana letters". So there are the alphabetical letters indicating what sounds like the "Hiragana" letters are. It is called "Roma-ji", literaly, it means "Roman letters".
Learning the Roma-ji
Scroll down this page above to the bottom, you'll see three charts in the page. The first chart shows the basic sounds of Japanese.
But notice that how to write the "Roma-ji" is actually different sounds in Japanese. The link below is the comparison of how different between how to write Roma-ji and Japanese Hiragana sounds.
When you read these "Roma-ji"s, you need to pronounce like "Hiragana" in this flashcard.
These may be useful for Japanese beginners to learn Japanese.