"There may be a line out the door and we expect our budtenders will be dealing with people who have a myriad of questions. So we wanted to offer information about the laws and about safe consumption," said Elan Nelson, a business strategy consultant for Medicine Man in Denver.
In south Denver, the staff at Evergreen Apothecary, located about an hour and a half from the Wyoming border, is ready for an influx of first-day retail pot shoppers with rented propane heaters, red velvet ropes and a security staff that will be on duty starting at 8 a.m.
"We'll be giving out special T-shirts," said shop co-owner Tim Cullen, "and my parents have volunteered to hand out coffee, juice and snacks to the people standing in line."
Longtime travel expert Arthur Frommer has predicted that pot tourism will make Colorado a new hot spot. But despite the fact that this sort of tourism has been lucrative for shop owners in Amsterdam, his daughter, Pauline Frommer, the editorial director of Frommer Media, said she's taking a "wait-and-see approach."
Leafly, an online database with thousands of user reviews of medical marijuana strains and dispensaries around the country, expects that starting Jan.1 there will be a large number of reviews written about the retail pot stores and recreational marijuana strains available in Colorado.
"It will help tourists in new locations find the right strain for the experience they're looking for. And once people find the right strains, we can tell them which retail stores have it and which retail stores are top-rated," said Leafly CEO Brendan Kennedy.
Prior to Jan. 1, Colorado High Life Tours has mixed sightseeing with stops at glass-blowing shops, marijuana grow centers and has offered customers "free samples"—because buying pot was not yet legal.
(Read more: Seattle throws birthday party for legal pot)
"You live and learn," said Vee. "On our tours, we're getting a lot of empty nesters that haven't smoked pot in 20 years. We've also had people who have never smoked pot take our tours and had one couple get high and so paranoid that we had to interrupt the tour and take them back to their hotel."
—By NBC Contributor Harriet Baskas. Baskas is the author of seven books, including "Hidden Treasures: What Museums Can't or Won't Show You," and the Stuck at the Airport blog. Follow her on Twitter at