Doe calls:
Doe Grunt is short and soft .25 sec
Doe bleat is about 1-2 sec long
Estrus bleat or Breeding Bellow is a dragged out bleat that may last 3-4sec
Bucks:
A contact grunt should last no longer than 1 sec.
A tending grunting is a serious .25-.50 sec grunts to a max of 4-5
A grunt that is used to indicate a buck looking for company (just a drawn out grunt) should last 2 secs

If calling in rut using tending/estrus calls 15 minutes, all other time every 30 min or so.

Rattling like burnie said, in times before or after peak rut keep it short and soft. Waiting a min of 45-60 min between each session. During the prime time, bring up the levels and duration, rattling every 30 mins or so. Also at this time I will add the rubbing, scraping, thumping and calling to the sequences. I mostly uses buck grunts but on occasion will throw in a doe estrus or bellow. I only rattle in one spot for 3 hours (so about 6 sequences during the rut) and will never rattle from the exact same location the following day.

When to rattle:
Prerut the lower light time is usually more productive.
Late Pre rut/ Prime Rut midday is my prefer time (10-3)

Where to rattle:
Location for me is the key to rattling and calling success. I find trying to lure game into a large open area or other areas that is deemed unsafe to their minds will cause them to skirt and most often wind you. I therefore choose to call/rattle in deep areas of transition. Close to the rut I will move as close as possible to the bedding areas of bucks and most often this is where I haul the most bucks. When doing this even though rut is on or very close, it is extremely important to start off soft, due to the close nature of the bedding area..once you have broke the silence sort to speak I will do as usual and bring up the levels. Also extremely important when calling is know your wind and use it your your advantage. Be attentive, have your shooting lanes mapped out in advance and aware of the backdoor (buck will often cirlce to lead with their nose!). Be ready, willing and able to shot in any given moment b/c they can appear in a flash..after I am done rattling the gun or bow is in my hands ready and I am panning with my eyes and ears on full alert.

Good luck and stick to it.