Hi Shirley,
I know translating Japanese addresses online can be difficult from my own experience too. I'll try to offer some tips from what I've learned but I'm no expert.
First think of a Japanese address like a bullseye - it starts at the broader city (i.e. tokyo) and zooms in to a specific building or house number. Also, addresses have kanji that can help you decipher them:
-Zip code 〒 followed by 7 digit number xxx-xxxx, at beginning of the address
-Prefecture 県 but can be 都 for Tokyo, 道 for Hokkaidō, 府 for Osaka/Kyoto
-City (shi) 市 - might be omitted
-Ward (ku) 区
-District (chome) 丁目
-City block 番
-House number 号
-If the house number refers to an apartment building an apartment number might be added
example:
〒 150-0041 東京渋谷区神南1丁目22-14
Zip code: 〒 150-0041
City: 東京 - this is Tokyo
Ward (ku): 渋谷区 -look for 区- this is Shibuya-ku
District: 神南 [Jinnan]
Chome: 1 丁目
Building number: 22
Apt: 14
Once you dissected the address into pieces (zip code, ward, district, chome, house number) you can try to decipher the kanji. I use diddlefinger.com to look up the address by zip code (〒 xxx-xxxx). This will give you the district, ward, and city in english and the map can help you double check the kanji. If I can't find it on the map I will type the ward and the district in english in google or wikipedia and compare the kanji translations with my address.
To write it in english just reverse the order:
1-22-14 Jinnan, Shibuya-ku, Tokyo, 150-0041 Japan
Hopefully someone with more experience will be able to offer better guidance though since the address system is a bit complex and I'm not very familiar with it. Best of luck :)