Marketing Strategy for software development and IT consultant

We are a full life-cycle software development and IT consulting company, specializing in Microsoft technologies - .NET, Azure, SharePoint, Office 365. Our target audience is IT managers at enterprises as well as SaaS companies or any company with an investment in custom applications. We need a marketing professional to help us fine tune and execute a 3 year marketing strategy. Someone with experience marketing in the Microsoft space and/or IT consultants would be great. We need a holistic marketing strategy but we feel the emphasis should be online marketing, specifically through LinkedIn.