While Mercury travels around the Sun every 88 days, its inclined orbit means that it travels between Earth and Sun only about 13 times per century. This time, transit is visible in many regions (including Europe and Africa), but people in North and South America have the best visibility.
I have to be very careful. If Mercury could speak (and it is the astronomical communication planet), he would say, "Do not look at me directly when I cross the sun." This damages your eyesight and you can not see Mercury even with a pair of eclipse glasses ̵
Instead you need a telescope or binoculars with a special sun filter. If you do not have one, "your local Astronomy Club may be able to track transit with special, properly-filtered solar arrays," notes NASA. You can not use a normal telescope or binoculars, even in conjunction with solar eclipse glasses, added the space agency.
The best bet is to go online. NASA's Solar Dynamics Observatory (SDO) satellite provides the best possible view of the solar eclipse, and NASA transmits views of transit in near real-time. To give you an idea of what you will see, you can watch the Transit 2016 covered by the above mentioned SDO.