Magoosh videos are structured to give you a very good preliminary outline of the otherwise scattered GMAT curriculum. Mike is comprehensive in his approach towards explaining the quantitative and verbal concepts. The content for quantitative learners is as good as you’ll get on the street, verbal is par (slightly lower) than other content providers.
I particularly like their approach of addressing GMAT as a 'logic' test - hence very good for beginners. However, for practicing on an advanced level, one might need to look at other resources too. Overall, a good buy for someone who is starting out with their preparation.