You should upload at least 1 new video per week when you are live. Members will expect updates at least once per week. You can cheat a little bit, however, by uploading recordings of your member shows or cam shows.
If you have a good quality camcorder, it's a great idea to record all member shows and upload these to a "Live Shows" collection on your website. This way, you can allow members to see shows they may have missed, and add to your site content.
Also, we don't recommend posting more than one video per week because members will begin to expect that and will tend to get upset if you're not able to keep up that pace. If you are producing more than one video per week, build up a reserve stash and release them over time - perhaps when you're on vacation.