To find the indexes, visit http://www.familysearch.org/, where you will see the page at left. Then click on Europe in the browse by location area, and all the collections for Europe will appear in alphabetical order by country. Under Ireland, you will find the Ireland Civil Registration Indexes for 1845-1958 (see Below).
Using the information from the census record, a simple search can be used for the births, marriages or deaths of any of the family members. Although the actual images are not available, some of them are on film in the Family History Library or through one of it's Family History Centers, and can be viewed there. Those that are not available in that way can be ordered from Ireland. A quick search for the Rosenberg family found the index entry for the marriage of Wolf and the birth of son Israel. Those results, found below, provide all the information needed to order the certificates.
Happy Searching and Happy St. Patrick's Day