Q1. How long should the challenge run for?
1 month or let previous winner decide
Q2. Should contestants be allowed more than one entry?
only one
Q3. Should there be restrictions on size. IE: 800 x 600 etc. ?
no, but no larger than 1024 x 1024
Q4. What would be the best time for the entry deadline? (12 noon, 12 midnight etc)
midnight
Q5. What would be the best time to end voting? (12 noon, 12 midnight etc)
midnight
Q6. How long should voting be allowed? (2 days, 3 days,...)
3 days

I agree with no posting of images in galleries until after challenge deadline