Sicile-Kira gives some more great advice in her book, Autism Spectrum Disorders, One of the first steps to take is to start "seeking knowledge". You need to contact, read, learn and document.
While all of this is important, remember to always try and take good care of yourself. Keep the lines of communication open with your spouse. Go out and do something unrelated to autism. Ask others for help and support. Family and friends are important and if you are unfortunate not to have anyone close by, again, seek out support groups in your area. This is all just the first steps to discovering more about your child and how to help them and you reach that wonderful soul locked inside.