How far back can you post? If I took a photo a week, a month, 6 months ago. How far back is too old to post. Is it ok to take 3 or 4 days photos at a time?
It's literally up to you whether you stick to "the rules" or not. It's called a "365 project" because the core idea is that you take a photo every day; plenty of people on here however are flexible with their own rules, and will post up stuff from whenever.
I would advise that you purchase a ace membership..not expensive..that way yu have 2 ore albums can add pictures on any kind and as far as I know as far back as yu like to share with us. your main or what they call default album allows you one picture a day. if you miss some days in between you can still upload them by using those days so you just change the date in the upload that is already provided for you to the one that you have open in your calender and that picture will go right to that open space..
No rules really. I know a lot of people use "fillers" if they can't/don't feel like shooting one day. I usually stick with one that I did in the past few days. But if you have one from 2 years ago that you feel like posting today, do it!
After becoming addicted to this site after only 3 days I bumped my membership to ACE so I could open another album to post my favorite new and old pics in. Definitely worth it :)