still you can start out simple and build from that. I give to two charities, Children's Healthcare of Atlanta and St. Vincents. I started out with a good amount per month automatically taken from my account.
I became acclimated to that "bill" much as one does their car payment or home payment. It is in the range of a small car payment per month now and I only chide myself for not boosting it more. The idea is to make it a routine expense so that you don't consider it a burden. The danger is forgetting to raise it or give to other good charities thinking you have done your part.
I do not mind people who do not give, I only mind the ones who speak up at charity drives at work with any number of excuses or complaints. It is not hard to find a charity to give money too, its hard to give