It really depends on how many you have finished. Ideally, you want to be able to trickle out content. Release a photoset and video per week is great and will keep things fresh for your members. If you already have 100 photosets, start with 50 and trickle the rest out. If you have 5, start with 2 or 3.
Also, there is no requirement to have photosets if that's not what feel like offering. It's YOUR site.