Is it difficult to keep bees?
No, but it's strongly recommended that you take a course and/or work with a mentor. You will need to learn basic bee biology and colony dynamics, as well as procedures for keeping your colony healthy and pest-free.
Your local Beekeeping club is a great source of info to help you be a better beekeper.
How much time is required?
The amount of time invested in your hobby is largely up to you. While there are certain times of year when a beehive requires more attention, you're free to open your colony and enjoy them whenever you like.
What about getting stung?
While you may get stung from time to time, many beekeepers work with their bees an entire season and rarely experience a sting. If you wear a veil and suitable clothing, the chances of getting stung are greatly reduced.
Is beekeeping an expensive hobby?
After startup, the expenses are minimal. For about $600-$800, you can acquire hive equipment, basic management tools, protective clothing, and enough bees to establish two colonies. After the initial expense, you can get more bees by splitting your own hives or catching swarms, and as you get better at it, you can recoup some of your costs by selling honey or other products of t