The discovery was recently announced in Nature; from the abstract:
Although Proxima is considered a moderately active star, its rotation period is about 83 days (ref. 3) and its quiescent activity levels and X-ray luminosity4 are comparable to those of the Sun. Here we report observations that reveal the presence of a small planet with a minimum mass of about 1.3 Earth masses orbiting Proxima with a period of approximately 11.2 days at a semi-major-axis distance of around 0.05 astronomical units. Its equilibrium temperature is within the range where water could be liquid on its surface5.This provides more information:
So, it seems to me, the only questions left should be pretty easy to resolve:
1. Is the planet really habitable right now, or is some terraforming required?
2. How long will it take to develop a space ship to get us there?
3. How long will the journey take?
On the last question, if we can increase the top speed of our craft by only 10X that of the Saturn rocket which took the astronauts to the Moon, it would take only 15,000 years to get there!