I always direct people to http://classics.mit.edu/Epictetus/goldsay.html for a taste of Stoicism. It is still tricky because what most Stoics thought of as "God" and what a modern reader would interpret as (the Christian) God are pretty different, but it is still easy reading. Other than that caveat it is pretty easy to understand.
As a sort of random aside, some of the most memorable sections of Epictetus for me are when he would referee to a pupil or discussion partner as a "slave". It always gave me a good chuckle. "My nose is running." "Why do you have hands, you slave?" e.g. quit complaining and wipe your nose. The color of comments like that really gives a feel for when the stoics think someone is being dense or wasting their mind. Some of the time now, when I am feeling particularly sorry for my self, Epictetus will pop up in my mind and call me a slave for complaining and it really helps me get over whatever random thing I was fixated on.
In terms of modern Stoic writing, I find Ryan Holiday's "The Ego is The Enemy" and "The Obstacle is the Way" (as well as his "Daily Stoic", although that's more of a daily devotional) to be very enjoyable and help to reframe the often hard-to-read writings of Aurelius, Seneca and Epictetus into actionable advice.