We have had a few inquiries on this one. Basically, the maximum size of the image file you will be able to upload is 512K. To ensure the display of your image in the highest rez possible, we recommend uploading your imagery at a resolution close to this. Poor quality imagery, mobile phone shots, stills taken from videos etc will be tagged as candidates for rapid deletion.
All of the imagery you upload will be logged against your profile and will automatically be filed in your personal gallery attached to your profile. Feel free to write anything you would like within the imagery fields for the shot, plugging your own site is totally fine - if you could remember us and donate to our enviro causes when you are rich and famous it would be greatly appreciated!