We are now beginning the Minor (Lesser) Rogation Days that lead up to Ascension Thursday. Like the Major Rogation, these are day to perform penance, fast, pray litanies, and petition our Almighty God to spare us from natural disaster, to bless our crops, and to save us from our sins. These were previously days of fasting before changes to the Roman Liturgy that took place even before Vatican II.
I also previously mentioned a wonderful booklet produced by Fr Christopher Smith, a priest of the Diocese of Charleston. This guide on the Ember & Rogation Day is a great ready for today. It can be downloaded from dropbox.