It could be useful for you to follow some contributions of Internal marketing literature. Internal marketing is an employee orientation from marketing philosophy. You could follow authors such as: Rafiq and Ahmed (1993, 2000); Lings (2004); Lings and Grennley (2005); Gounaris (2006; 2008)
HR interfaces with marketing I guess in many ways; selecting the right people to start with (might be by outsourcing).
Training & development, for the employees in the marketing department in order to get them equipped with the latest knowledge and techniques.
Building their skills and competences.
It could be by the incentives & motivation for their employees; example when increasing the sales or reaching a specific points etc. (which has a direct impact on organization's profits this could also be done nonmilitary such as choosing the employee of the month). There are also performance appraisals.
Bench marking with rivals (the marketing department) etc.
The first consideration for HR and marketing interface commences with the Brand image of the organisation and its identity as an employer. Building up a corporate image with sound reputation will automatically attract the best employees from the job market. This will in fact be the first step in creating a sound pool of employees. Once this is accomplished the organisation must head for nurturing internal PR as a subset of internal marketing to retain the workforce. This will ensure a balanced environment that not only attract but also retain the best of employees. It should always be borne in mind that happy employees generate happy customers.
If you consider the service profit chain concept (Hasket, 1994) you can see how HR practices influence employee satisfaction, productivity & output quality through which increase the service quality and lower costs (by creating value) which increase customer satisfaction and loyalty and resulted with Lifetime value, Retention, Repeat Business and Referrals.
Check out the literature on 'internal marketing' which has been described as a marketing-like approach to people management. It applies marketing concepts such as segmentation, targeting, positioning, communication to the realm of HRM. At best it provides a set of prescriptions for HR management; as worst it's a useful metaphor.
All areas in management are inter related and inter dependence to each other. There is no isolated function. Starting point of any business operation is to identify customer needs. Then the business think of how to produce, when to produce, what types of employees are needed to perform each and every function(production/ operations, finance, marketing, HR and accounting), how much money to be invested and other resource etc. On the other hand every one in the organization has direct or indirect responsibility to promote marketing activities. Having satisfied internal customers is essential to succeed in the market place/space. It is one of the important responsibilities of HRM.
Look into Porter's value-chain model which appreciates the core competencies relationships and which infers that HR and Marketing are inter-related through coordination, cooperation and mutual communication in the identification of needs and requirements to achieve the common objectives of the organization. Another model where you may appreciate that relationship is "process management" which eradicated the functional management or silo effect and which in return appreciates the cross-functional collaboration between functional departments.
I see the relationship from the "Musketeers' Motto: One for all and all for one".
HR-Marketing interface area in my opinion is: Strategy, Technology and Skill (STS). Training and skill development is of utmost importance for effective product, process and pricing. Marketing today is customer-centric. There is huge competition on account of shorter product life cycle and customers’ price sensitivity. In such a situation, firm’s human resource skill coupled with technology and strategy will help developing appropriate innovative product, packaging, pricing, channels and operating models. I am tempted to provide example of Siemens, who made a conscious decision to make SMART (Simple, Maintenance- friendly, Affordable, Reliable, Timely-to-market) products for emerging economies like India.