A Black Bear is a black bear...30-06 will be more than adequate to deal with the largest black. If you're hunting with a guide in bear country I'll bet he's packing some serious bear medicine in case you encounter a brown. If I was on my own in Alaska bear country I'd probably want something beefier for security.
I still have my doubts of the ability of any hunting round to bring down a charging brown after he's decided you're dinner. Personally for that scenario I'd want a 12ga loaded with a mix of slugs and the heaviest gauge buck I could find.
Being a bowhunting I've always been fanatical about scent control. Whether it's sprays, carbon clothing etc. I've tried it. The best thing that I have found for eliminating human scent is Betadine. It's been used in hospitals and homes for decades as a defense against infections on minor scrapes and burns. It can typically be found near the pharmacy in any of the major "one stop shop" stores, and a bottle will last multiple hunting seasons.
Before every hunt possible I...