The Official Guides have probably the best explanations to the problems. However, jumping directly to the OG questions is not a good strategy. Even if you want to practice questions, you should go through the concepts,practice the OG questions and then move on to the next topics. I'd suggest that you get some quality reference books for the different areas/topics.

The Official Guide 12th edition does have some good explanations, but others are a bit technical or limited and often do not give you the sort of strategy advice that you need.

For and OG problem that you do not understand the explanation well, you can type in a small part of the question in quotation marks, for example "(insert the first few words of a sentence correction here)." I have little doubt that most OG questions have been discussed on Beat the GMAT and so you will get a good explanation for OG questions instantly.

This, however does not give you the full strategy that you are looking for...for that you will need Veritas, MGMAT, or other resources that teach you how to approach the problem. I would put away the Barron's and move to something else...