Share '"Apply for job" functionality and Attachments'

On my job board PostJobFree.com job seekers may apply for job. However currently PostJobFree does not allow them to attach resume to their application. What do you think - is this [resume attachment in application] functionality important for recruiters? If so -- what's the best way to implement it: 1) Should file size be limited? If yes - what size should be ok? 200K? 2) Should files with extens…