No extra spacing at all when typing. Even after the period mark there is enough space built in the character 。。。。。。............ <--see, a lot more spaced apart than the roman-alphabet's period is.

You write a perfect Japanese.
You don't need any space in Japanese but you need a comma in a long sentence and a period at the end of a sentence.

Here is an example.
私は日本語が少しできるので日本の会社で働きたいと思っています。そして日本人の友達をたくさん作りたいです。
私は日本語が少しできるので、日本の会社で働きたいと思っています。そして日本人の友達をたくさん作りたいです。
Which is easy to read for you? I put a comma after the first clause to describe your reason to want to work in Japan.

It's all very difficult for me to read! :P (I'm still a beginner.) I understand what you mean about the comma though. Thank you very much, to both of you. Your explanations were very clear.

Ganbattekudasai!! =) Frank!

drfranktm,

Your sentence is perfect!
We don't use any spaces between words. But we put a space between sentences just like English writing. As for punctuation, I don't think there are rigid rules. Here is a guide for biginners.

1. Before or after a clause
2. Before or after a phrase indicating time/time period or a place
3. After a long subject

For example,

1. When I was a child, I would draw pictures.
私は子供の時、よく絵を描いていました。

2. I went to Canada during my summer vacation.
夏休みに、カナダに行きました。

3. The girl playing tennis over there is my sister.
向こうでテニスをしている子が、私の妹です。

I think Japanese is a more flexible language than English and French. So don't be shy!

-Hiroko

Hi I'm a Jang Byung ryul, Korean studying English and Japanese. There is no need to space in Japanese. Hiragana or Katakana distinguish own meaning as writing [,]or[kanzi漢字知ってますよね！].
For example, 私と彼女は、遊びに行った　私と、彼女は遊びに行った。has little diffrent. first one is emphasizing I and She, second one is emphasizing only I