At least on my campus this is how it works:
Info session is organized (
HR):
At the info session you'll have the chance to speak to Partners/associates/analysts/staff/etc depending on what kind of firm it is,
HR will also have reps there in case you have any questions about
HR stuff.
Resume/Cover letter screening is done:
Usually managers/partners are involved in this, according to what I've heard
HR is not involved in this - purely a "volunteer" task to beef up the involvement of senior peeps who want to get ahead.
Interview invites are sent:
HR will send you an email thanking for your interest and inviting you to choose a time slot to interview
Interviews:
1st round usually done by people who have been in the firm for 2-5 years.
2nd round usually done by senior managers/partners
Offer is made:
USually a senior manager/partner will call you to communicate the offer ASAP. You will also get an email and a package in the mail with all the details and the legal stuff (these two done by
HR)