Winneronline have published their version of the Online Gambling 10 Commandments.
Their biblical entries may seem fairly obvious, but are a good check guide when you join a new online casino

#1: Thou Shalt Know The Local Law
#2: Thou Shalt Know Thy Casino
#3: Thou Shalt Play For Free
#4: Thou Shalt Demand Adequate Customer Support
#5: Thou Shalt Know Thy Payout Options
#6: Thou Shalt Check Out The Bonuses
#7: Thou Shalt Know That All Games Are Not Created Equally
#8: Thou Shalt Protect Thy Data
#9: Thou Shalt Play To Win
#10: Thou Shalt Enjoy Thyself