Sites to read carefully

For planing the Hokkido trip
http://www.jnto.go.jp/eng/
http://www.jrhokkaido.co.jp/index.html

Bike trip stories and info:
http://www.geocities.co.jp/SilkRoad/7808/
http://www001.upp.so-net.ne.jp/meisaku/hokkaido/index.html
http://www.horae.dti.ne.jp/~tabi-pr/s_bike1.html
日本語の大挑戦ですね〜
and:
北海道單車騎士的資料收集：http://www.outdoorjapan.com/activities/cycling/activities-cycling-routescourses.html

當然到jcc(日本單車協會)找資料
http://www.japancycling.org/v2/

單車遊北海道的遊記
http://www.journeyintojapan.com.au/Cycle_Hokkaido.html (澳洲人)
http://www.logos.t.u-tokyo.ac.jp/~sugimoto/cycle/hokkaido95.html(日本人95夏)
http://homepage.mac.com/freeman588/bike/index.html(台灣人)
http://www.japancycling.org/v2/inter/reader/jerry/(台灣)

Also, visa info:
http://www.jnto.go.jp/eng/arrange/essential/visa.html
http://www.mofa.go.jp/mofaj/toko/visa/annai/visa_2.html
Anyways, US and Taiwan citizens may stay without prior visa appication for 90 days.