Hi Tal, there are still a couple spots for the 28th (er, that's tomorrow already...) if you'd like to submit.
I wouldn't worry too much about whether your submissions fit in solely on the basis of length--we've had people submit fairly short stuff before, including flash fiction (I've submitted one or two flash pieces to this group myself). As for poetry, that's definitely outside this group's usual focus; you're welcome to submit it but may find that people don't have too much to say about it (I know I'm not as confident critiquing poetry as I am critiquing fiction; I suspect that I'm not the only one but there may be other poetry readers/writers in the group). You're welcome to submit anyway and see what happens--if you submit some poetry and find that you're not getting much useful feedback from this group there's definitely no obligation to keep submitting that kind of work.
Submissions typically happen every Monday, and as I mentioned, there are a couple open slots for tomorrow if you want to try it. Details on how/where to submit are all in this thread. Let me know if you do decide to submit tomorrow so I can put you on the list if you do.