May I suggest using the Mormon Church genealogy libraries or their on-line Family Search service? (
http://www.familysearch.org/Eng/Library/FHL/frameset_library.asp)
To be honest the on-line service does have flaws in that the IGI is not comprehensive. It only includes what their transcribers decided to transcribe and so there are many, many gaps. That said there are still thousands of entries from all over Ireland.
The search also brings up 'Ancestry File' and similar other databases. These can be useful but must be used with caution. Often the information entered has no basis in fact and is based on assumptions by the researcher. I have seen quite spurious dates entered for births based on completely inaccurate 'guesses' as to age at death/marriage.
BUT - Where the Mormon (LDS) church shines is in their libraries. Cross your fingers and any other appendage you possess and hope there is one near where you live.
They have access to a huge range of microfilmed original records which you can access free (well almost - there is a charge for postage sometimes).
My local library got me the church records for the two adjoining RC parishes I needed and I have been transcribing them ever since. Also 1901 Census, Griffith's Valuation and 1833 Tithe books.
Let the Gen Centre go hang - they aint getting my cash!
Jim
Perhap I should add that the staff in the actual library in Ballinamore did provide access to their newspaper archive free and allowed me free access to browse some of their old documents - eg lists of old townlands etc.