"秘笈"英文係咩?

It depends on what you want to say.

- Secret Manuscript ... for Kung Fu.
- Receipt... for cooking
- Hints, cheats, tips or walkthrough... for playing a computer game.

~Secret recipe
~Secret booklet

秘笈"英文係 tips

It is better you let us know what you are going to say so we can do a better translation instead of one word.

"秘笈"英文係咩?
秘笈: a secret of …; the tricks in …; a knack to…; a tip on…

knack : 妙法, 訣竅
trick: 竅門, 招數, 手法
secret : 祕訣, 訣竅; 祕方
tip: 訣竅, 情報, 祕密消息

2010-12-14 16:41:38 補充：
e.g.
(1) There's a knack to baking agood cake.烘烤美味的蛋糕是有竅 門的。
(2)Igave her a tip on how to concoct anew kind of soup. 我教她配製一種新湯的訣竅。
(3) Daily practice is the trick in learning a foreign language. 每天練習是學會一門外語的訣竅。
(4) One of the secrets of good health is regular exercise. 身體健康的訣竅之一是定時運動。

我推薦您一個非常不錯的英語學習網站，里面有很多非常不錯的學習資源：

http://www.hkenglishstudy.info

希望可以幫到你!

"秘笈"英文係

Secret Manuscript

'bible'
但係都要睇個句野想講咩。

secret book or collection od of books
Couldn't look up from the yahoo dictionary??

可以係.. secrets