For gov't health care, it is not a "marriage" that entitles you to coverage. It is residency. Once you are a legal resident in the province, you have to wait 90 days before you are eligible for provincial health care. Doesn't matter if you are a temporary foreign worker on a work permit and no relatives in Canada....itis to do with your residency.
There is provincial coverage "repalcement" that you can purchase. So, if you are in Ontario, you can purchase what is called "OHIP replacement" insurance that will cover you for that 90 day waiting period -- but you must be resident and in that waiting period to get your OHIP replacement. IE/ you can't be there as a tourist, iykwim. The ohip replacement will cover you exactly as ohip would, but you pay for it, as you pay for any other type of health insurance. The last time I purchased ohip replacement (for an employee brought over on a work permit) it was not expensive, about $150 for the 90 days, but that was in 2001, so expect 9 years worth of inflation!
For employment related benefits I assume you mean group health insurance, such as prescription and dental coverage through an insurance company such as Great West or Sunlife, for instance? If so, the requirement from these insurance providers is that to be included in their insurance plans you must have OHIP (or ohip replacement) coverage. (Or whatever it is called in the province you are going to be in, just using Ontario as an example again). So, once you are resident, have your provincial coverage or purchased replacement coverage, your husband can apply to have you included as one of his dependents. If you are not married, but living common law, then it depends on the insurance provider and the plan details that they have negotiated with your husband's employer -- some companies may have negotiated a price based on spouses only, while other employers may have negotiated prices based on including common law spouses -- so that part is totally down to your husband's own insurance plan. The only way to get 100% accurate information is to phone the insurance company directly, and he will need his plan number and member number so they can look up the terms and conditions.
HTH
