The Church History Library for the Church of Jesus Christ of Latter-day Saints houses the archives and historical library for the Church. This resource now has their catalog online (beta). To find it you can use this link or go to the Church's website at www.lds.org and then choose, Menu>The Church>History.
From the Church History Library page you can search the catalog as well as search the index for the Journal History. This new website also has Research Guides and Digital Collections.