I am sure that the company management must not have employed you if they felt that there is no need for an HR person in the company. So plz do not underestimate yourself .
With respect to the salary aspect; what you can do is to initiate some basic HR activities in the company (like a recruitment process,attendance,leave policy,forming basic job description for all positions) .Once you show results , you can always ask for a salary raise;which the management will surely not deny..
In case you need any more help refer some of the sections in Citehr itself which give you a detailed description on how to start a HR department in a new company. You will surely get some extra info..
26th April 2011 From India, Mumbai