Guide _ in a marketing you will think, record and document all your ideas, products and services offering, price, distribution channel, programs, sales direction, customer segment and so on. I have experienced whereby I suddenly realized that my business is not going on the right direction because I didn't follow my marketing plan. Have you experienced that? Or perhaps you suddenly realized that the thing you do know supposed to be done many months ago because you forgot about it? And you forgot because you don't jot it down and plan for it? This is what I mean that marketing plan as a guide. I cover this in my Marketing Plan Breakthrough S6PEC.
Strategy _ similar to business strategy, marketing plan will capture strategies required to support your business strategy. For example if your business goal is to achieve 20% increase in sales, your marketing strategy would be to 1) introduce new product, 2) increase price for premium offerings, 3) recruit more distributors and offer commission scheme and so on. Strategy is king. When you can see your business in totality, I can assure you that you will find it easier to manoeuvre. Marketing plan is the place to address all these issues.