I just did my taxes last weekend, filing as married for the first time. My spouse is overseas, so I left the SIN # blank, reported his income, and claimed the spousal amount. I checked today and my return has already been processed, no issues.
Really, you don't need HR block. Just go to the CRA website, download one of the authenticated tax softwares (I used Genu tax). If you go with Genu Tax, definitely select the comprehensive interview. It takes you through step by step, asking you many questions, this way you are able to claim all credits you may be eligible for. Then submit it. It took me about 2 - 3 hrs.
Or you can go to one of the Volunterr Tax Clinics operated by CRA to get your taxes done for free. But you have to be below a certain income level to be able to use this service. Check the CRA website to see if you qualify.