As an adjunct lecturer of history (and a history major during my undergrad years) I often tell my students that if they really want to begin to grasp an event or a person to first check out Wikipedia. The response to this suggestion is usually one of surprise. Why?
Most history teachers or historians do not like Wikipedia for at least two reasons. One, because it is not scholarly enough (even though most posts have scholarly references at the bottom of the page); and second, because the author of the post is anonymous and posts can thus be updated or written by an anonymous other. Perhaps this other is not a qualified historian!
The philosopher Jacques Rancière (who I have just started reading with great delight) in a recent interview discusses reasons why there is a certain distrust of things on the internet. One of the reasons is that there is an accessibility there. It also allows the bypass of the teacher. In short, anyone from any station of life has access to literature on the net. So, when people decry the use of websites like Wikipedia there may be an underlying distrust of the student to understand what is real historical knowledge. Wikipedia may in fact be a real democratic way of learning that truly levels out the "enlightened" teacher with the "ignorant" student.
So back to the question. Yes, I always tell my students to check Wikipedia first because it is frankly trustworthy in most occasions and universally accessible; it is the method I use. However, I always follow that up with reading the actual books and articles that deal with the subject as well, if the Wikipedia essay has led to my interest in the topic.
NOTE: love the picture because Rancière looks lost on the side of the road or something.
For more information see Nina Power's interview with Rancière: