I don't think you'll find Mississippi's laws on access to be that different from any other area as far as private property is concerned.? Technically, trespassing on property is illegal unless you have the owner's permission.? If you plan to be on unoccupied property or on property in the occupant's temporary absence, be sure to have written permission that specifically gives you access in that circumstance and specifies what you are allowed to do.? Offer to relieve the owner of any liability responsibility as part of the permit text; it'll help to get the permission in the first place.
I suggest you visit
http://www.mississippi.gov/ where you can find a lot of links to info on laws, agencies, local governments, etc.? If you want to read some of the state legal code visit
http://www.mssc.state.ms.us/ where the Supreme Court website has a link to current state laws on all subjects.
One tip: Don't waste your time asking for permission to hunt on any private property registered with the National Historic Register or the more rarely applied state equivalent. As part of the registration approval, the owners gave up certain innate property rights to gain the protection the laws provide. Even if an owner gave you temporary permission to MD, it wouldn't be valid and you would probably almost certainly be legally pursued by the state or feds for removal of "artifacts" and destruction of historical property. The nationally registered sites usually have a marker signifying that distinction. A state registered site may not so if it looks old or if you think it's the site of some historical event, verify the MDing restrictions before you do anything!
You'd do well to try to make some connection with locals who also MD. Although Mississippian's are generally hospitable, it may take you awhile to fit in as being "from around here." More simply put, you'll have to make a little effort not be classed as one of the "Damn Yankees" or a neo-carpetbagger especially with older people. You will be fortunate in that you'll be in an area that sees a good many out-of-staters (usually temporary residents) that come to attend Mississippi State University at Starkville or, to a lesser degree, Mississippi University for Women (which isn't any more) at Columbus.
As to your snakeboots question, while such protection may be a good idea when traversing areas with a lot of tall grass or brush, they're a bit stiff for doing a lot of bending, kneeling, etc. when actually MDing.? In fact, more locals that I know of that have been bit were struck on the hands or lower arms when they bent over to pick up something.? The snakes were of the smaller varieties -- pygmy rattlers, copperheads, cottonmouths -- rather than the biggies like canebrake or timber rattlers.? We have a lot more innocuous varieties than we do dangerous ones.? Some can be rather fascinating to watch.
Best wishes
Wayne Anderson