Establish Your Care Team
Many breast imaging centers will refer you to a "Nurse Navigator" who will guide you through the process and help setup appointments with doctors. If you choose a different clinic/center for your treatments they will most likely have their own nurse navigator.
Your Oncologist will be someone you will have in your life for a long time, so make sure to pick someone you feel comfortable with in terms of communication style and approach.
Also make sure you feel comfortable with the staff at the clinic/center as well (front desk, nurses, billing, scheduling) as you will interact with them many times.
If you may need chemo, make sure to assess the ease of access to the facility and comfort/environment of the infusion room as you may prefer a clinic/center with a specific type of feel.
Your breast surgeon will remove any cancerous cells via lumpectomy or mastectomy, and remove any affected lymph nodes. The breast surgeon will help you determine the best approach (lumpectomy or mastectomy) based on a number of factors. You will see this doctor several times throughout your recovery and during the next few years for monitoring.
A plastic surgeon will help you determine if it makes sense to do some work to even out your breasts after a lumpectomy or a single mastectomy, and/or reconstruct your breast(s) after a single or bi-lateral mastectomy. Find a surgeon you not only feel understands what you want (end result) and has a solid reputation, but ideally a surgeon with a great staff (PA, nurses, reception) as you will see this doctor many times throughout recovery and in the future for maintenance.
A Radiology Oncologist will provide radiation therapy if needed. They will meet you and discuss the treatment plan then setup your "fitting" for the radiation equipment.
Oncology Physical Therapy
An Oncology Physical Therapist can be used for therapy during chemo as well as pre/post surgery. You will want to get an appointment right away before any treatment/surgery so the therapist can assess your capabilities. The PT will help tremendously in your recovery focusing on healing, range of motion and strength. Find a location close to your home or work as you will go once or twice a week for several months.
Acupuncture can help with many steps of your treatment and healing process, you can have acupuncture to boost your immune system before procedures as well as help with side effects and healing.
Primary Care Doctor
Now that you have been diagnosed with cancer it is a good idea to ensure you have a Primary Care physician who has experience working with breast cancer patients and is someone you feel comfortable talking to about symptoms you may experience and work with you and your Oncologist to manage side effects and maintain your health post treatment.