Brightly lit rooms, enticing menus and a smiling staff greet customers from the entrance of the Green Door.  What initially might seem like a favorite coffee bar is actually a San Francisco dispensary.

The Green Door in San Francisco is one of the oldest medical marijuana dispensaries in the United States, having opened in 2003.

Gone are the days of dark backrooms and transactions made in secret. Bright displays show off available products while daily menus offer unique-sounding flavors such as Bombay Cherry Doughnut and Platinum Cookies. Rather than baristas, the staff is made up of knowledgeable "budtenders" who can offer insight into the numerous products available.

If Proposition 64 passes in November, it's expected that the number of marijuana dispensaries will increase throughout the Bay Area.

So what really goes on in a dispensary?

From weighing out bulk product to patients enjoying their merchandise, I follow the marijuana buds from start to finish at the dispensary.

Bulk bags of marijuana are received from vendors and weighed by hand as they're packaged for individual sale.

Maurice Price, who has been working at the Green Door dispensary for two years, weighs and packages cannabis buds. Price says he's in support of Proposition 64. He says that it would cut down on the number of people jailed for illegal marijuana use.

Price picks through the bulk container of marijuana to find the best buds for each package. He wants every client to get the best product possible, no matter what bag they buy from the counter.

Staff members grind down marijuana that doesn't meet the tough standards for full-bud packaging. Then they sift the finer material and use it to fill premade joints. Every day they make at least 750 joints.

Ricardo Rodriguez has been at the dispensary since January and really enjoys it.

"We're like a big family here," say Rodriguez. "We all help each other out. Everyone is very supportive."

After the marijuana is packaged and ready for sale, it's taken downstairs to the main shop. An entire back wall is lined with drawers full of different strains of marijuana. The Green Door dispensary carries an assortment of strains that changes daily.

Alongside the buds are edibles of all varieties. From chocolate bars and macaroons to lozenges and cotton candy,  staff say the marijuana-infused foods are a popular treat with patients.

Upstairs from the shop is a lounge where patients can use the products they've purchased. Green Door is one of only a few dispensaries in San Francisco that offers this option.

In a large room full of windows and skylights, more than a dozen patients sit at tables or lounge on couches. In the corner, a small kitchen offers paper cones and rolling papers, alongside dabbing rigs and vaporizers. Nic Ash, a patient of Green Door, enjoys rolling a "backwoods blunt" while sitting with friends.

State financial analysts say that if Proposition 64 passes, shops like this could bring in hundreds of millions, or perhaps more than a billion, dollars in revenue.

But a variety of groups, for many reasons, are opposed to the proposition. Some small growers say they’ll be pushed out by “Big Marijuana,” whereas other groups are concerned about children being exposed to the drug.

But Alicia Darrow, the chief operations manager of Green Door, says it should be legalized. “It does create competition, but that's standard in any business," she said.