My company is 6 months old and an S Corp. How do I bring on 2 additional shareholders to be directors/officers?

There is a lot to your questions here and you need to hire competent tax counsel. A couple of points:
1. The losses to date should be yours by making the proper tax elections when new shareholders buy in to the corporation.
2. How are you going to determine a proper buy in for the shareholders or stated differently, what is the value of the business?
3. Always, and I mean always, be reluctant to give up control of your business. Do you have to give them shares to have them work for you? If so, you must keep over 50% of the shares. Do not make a mistake on this as you will live to regret it.
4. If they provide services and are shareholders they must be paid "reasonable" compensation. This must be discussed with your tax attorney.

Hope this helps.

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