you mean , how to post a picture in the critique corner? you need either external hosting, or you need to sign up at clubsnap gallery to host your images. being new here, you might want to read this link here.
and the relevant link to posting images is included in that thread.
please note that for critique corner, there are guidelines, some that i can remember off the top of my head include:
1) you need a writeup to explain what you wish to portray, why you took the picture, something of the sorts
2) one picture per week
3) what you would like critique about
you may want to read the relevant critique corner guidelines in the critique section. cheers, and welcome to clubsnap. happy posting!