I've been working as apprentice in a Software development company for 7 months now as a part timer. Now, the chief of staff wants to add me to the development team as a full timer. I made some calculations about the paycheck and the standard salary for someone starting in the company is slightly lower in amount of $/hours than the one I was being paid before. I really want to stay in this company for at least some more time but I don't want to be paid less than before (even if it's almost the same). I don't have experience negotiating and don't want to fuck up. Any tips about how to negotiate your salary?