Good morning,
First, your husband would have to apply to become an Irish citizen based on his decent from his Irish grandfather. The Department of Justice is the government body that regulates citizenship matters here in Ireland.
www.justice.ie is the website, click on 'Site Guide', then 'Background Notes', 'Citizenship Information Forms' which will take you into a page with 'General Information on Citizenship'. This link will take you through the separate individual routes that a non-national can become an Irish citizen. It lists what he would have to get (paperwork like birth certificates, marriage certificates and such) to make his application based on descent. You can download the forms on the website as well.
The following link 'Post-nuptial declarations' for citizenship is the route that you would follow, basing your position on your husbands Irish nationality. I know that since 2002, spouses are not automatically given Irish citizenship just be being married to an Irish national, instead you would have to apply after being married for 3 years to said Irish national going through the Naturalization route. I know that sounds a bit long, but the important thing is that a non-national married to an Irish person can work in Ireland without the hassle of a work permit or work authorization (which is the usual hang-up about coming to another country), so although you would not be Irish yourself (not right away anyway), you would be able to avail of some of the 'privilages' of being a citizen.
One thing I'm not sure about is how quick the process is for your husband to become Irish through descent (how long the application process is, fee, that kind of thing). Also I don't know if there is a waiting period before he can then use his 'Irish citizneship' to get others into the country. For example, if he was granted citizenship on a Friday, could he then immediately use it for you to come over and start work the next week. (This is not a real situation example of course, just trying to get my point across
If you contact the Department of Justice directly (contact info on their website) they should be able to give you the ins and outs of it all. Also, if you're interested, information on work permits/work authorizations and general Irish employment regulation is available on
www.entemp.ie The Department of Enterprise, Trade and Employment handle that.
For general info on moving over here, try
www.movetoireland.com. I just recently found this website and I think it's really helpful. All kinds of info about all issues of living in Ireland (tax system, housing, cars, banking, cell phones, pets.....the lot). It's updated frequently and has loads of links to various topics that you have to consisder when moving to Ireland.
Also,
www.unison.ie is the link for the national newspapers in Ireland, just to keep up with what's happening over here
Good luck,
Regards, Maria