Good question! If you are a total layman popular scientific magazines or blogs like the Scientific American from Nature Publishing Group or scienceblogs.com are a first source to spot which kind of views are represented in the community. Articles therein are mostly written by current or former academics and scientists with educational background in a scientific branch and contact to universities and researchers. And they skim the most important articles in the primary literature or visit conferences in their branch. But don't rely on single articles, always compare several sources, but the necessary background to understand such articles is often lower as a broader audience is focused by those publishers.
From there you could dive deeper into the scientific primary and secondary literature over Google Scholar/Books by searching and reading review articles that summarize the longer or recent past of a distinct scientific field. In the best case such review articles are written by several authors. In scientific fields like for example dark matter physics you will not be able as a layman to get a picture how much percent roughly believe in the current paradigm or an alternative theory. Searching on Google Scholar with intitle:"name of theory/paradigm" might give you some hint how much researchers work/favor alternative theories and open questions.
(Hand) Books written by several leading scientists in a field are in general a reliable source, though often not covering most recent developments in a distinct field. Textbooks will often need a solid background in distinct underlying theories (consensus on these?), even for academic graduates and interdisciplinary researchers in a field. I think a total layman cannot understand them and textbooks are often written by experts of a distinct view/theory, not of competing theories, and not the main spot to discuss alternative theories, rather journals.
Concerning life sciences, published meta studies that analysed and evaluated the data of many published smaller former studies that refer to a distinct scientific question like for example "dying of bees" are a good first source. So here we have to distinguish between views/theories and data. But, if meta studies show that the data amount is too low or contradicting other data, then there can be no consensus concerning a distinct question.
If this all doesn't help you, skeptics.stackexchange.com is a very good site to ask which theory/cause is currently favored by the majority of the scientists or what the data favors. But like Scholarpedia and Wikipedia you cannot be sure the answers or articles are written by scientists with educational background in the related field. But as a layman, I think it is rather important to know if the majority agrees, are there ongoing discussions, is the scientific community in a field split up, what is the current paradigm and how much research is ongoing on alternative theories and open questions. Popular scientific magazines/blogs normally cover such questions. If you are interested in more details, asking on a related scientific sites on Stack Exchange is another option to get often a discussion/answer by several scientists or students in a field.
I agree with the comments and want to explain that one major problem with finding a "consensus view" in the scientific literature is that basically it is the job of scientists to try to falsify the current paradigm/theory/consensus, especially when there exists a strong consensus, but the theory is incomplete or doesn't explain everything sufficiently. But one also has to distinguish here between theories and facts/data. If you ask for instance if dark matter can be the only add-on to explain rotation velocity of stars in galaxies, then most astrophysicists would currently favor this explanation/view, though there are also astrophysicists who work on alternative theories/explanations. Those might get also attention (more than they deserve) in popular scientific magazines and this good from my point of view to foster falsifying theories. You could also ask is there a consensus on the general relativity theory and likely most of the astrophysicists would say it is currently the best theory we have before a unification of all physical theories. There would probably be a bigger consensus that space-time is a physical entity than general relativity is the final theory because, again, there are few theories in physics that have a "final" tag. The evolution theory in biology is maybe not perfect and covering everything, especially genes and epigenetics, but mutation and selection is the paradigm I would say 99% of biologists agree with. For climate science, to my knowledge, most in the community (>90%) agree that the data in conjunction with theoretical simulations points to human-made global warming. I show these examples to explain to you that there might be a strong consensus on data rather than a theory concerning a distinct question. In popular scientific magazines/blogs this difference can be more undermined than in scientific journals or books.
The minorities are and have to be covered in popular science, maybe also in a stronger kind than their alternative theory/view is really represented in the community. So if you really want to know if the majority believes in one theory, if there is a consensus, always check several of above sources like wikipedia, popular scientific magazines and blogs! You can also make a poll among scientists on consensus on data and/or theory, and Stack Exchange is maybe the best place for this currently, if you chose sites with a high density of scientists or expert/layman ratio frequenting it like mathoverflow.se or cstheory.se, stackexchange sites like physics.se are too much diluted by laymen for a poll to a mainly scientific audience.
