Hi Priya,
As you are from recruitment, you must be familiar with the selection process and moreover its an intra department transfer. So, you must be aware of the job description / role.
Let us get down to the knowledge part. There are lots of links, material , documents available in SCN and also there are other websites which will guide you in understanding the SAP HCM. You have been trained in HCM and you know the modules well and you must have gained some knowledge.
As far as interview goes, usually interviewers check the the following:
1. Technical expertise. - Technically strong in modules
2. Domain Knowledge - Good domain knowledge
3. Business Terminology - Familiar with business terminology and process
4. Psychological capital - Well balanced and work under pressure etc..
5. Execution Expertise - Ability Project execution
6. Analytical skills - To anaylse business requirements and provide solutions
7. Communication - Good communication skills to interact with clients
There are other factors as well depending on the interview panel.
If it is a support project, they might be looking for someone who an analyse well and provide solutions as you will getting the tickets based on the severity.If its an implementation, then they look for who are strong in technical (configuration, coding testing etc..)
Brush up your technical knowledge by revising the tables, Tcodes, Reports, Features.Work on configuration and also you should be able explain how a process works. eg: How to create absence quotas, How Personnel actions works. What is the payroll process. US Taxation process etc...
OM -- Organisation Structure, Objects, Reports, Delimit, Position etc..
PA - Infotypes, Time Constraints, Personnel Actions, Dynamic Actions, Reports Enterprise Structure, Personnel Structure etc..
PT - Work Schdules, +ve / -Ve time Mgmt, Absence & Attendance Quotas, Time Evaluation, Reports etc.
PY - Payroll Organisation, Payroll Process, Payroll Reports, Wage Types, Taxation etc. (US Specific Taxation, Garnishment,US specific Infotypes).
I suggest you not to mug up anything. Just try to be yourself and present it.Be confident. They look for how good are you in understanding the business process and how best you can provide the solution. every time you may not find a solution but at least your analysis should at least somewhere near to finding a solution.
As you are beginner, explain your aspiration to become a SAP Consultant and your goals. Definitely they will consider you.
I wish you good luck and All the very best.....
Madhav.