Liturgical practices have changed in the last generation. It's fair to wonder what's going on with communion these days. In parishes around the country, I see everything from the reconstruction of altar railings to people falling on their knees at the front of the communion line. Folks cup their hands in the throne-like gesture taught in communion prep classes these days, or perform casual host grabs that seem almost unconsidered.
So here's the present teaching. Yes, the communion fast is still in force. Details are important here: 1) Water never breaks the fast, so don't dehydrate to prove your devotion. 2) The fast from food and drink besides water is one hour before reception of the Eucharist. 3) Sick and elderly people only need fast for fifteen minutes before communion. Caregivers accompanying such people may follow the same guidelines. 4) Sick persons may take medicine and non-alcoholic liquids unrestrictedly.
In Canon Law, seven regulations apply to proper reception of communion. The fast as outlined above is one. Anyone who's received First Eucharist is obliged to receive at least once annually, preferably during the Easter Season—the so-called "Easter duty." Receiving in the context of Mass is "most strongly recommended"—again, with exceptions for the sick and homebound, or communities with no access to a priest.
A fourth regulation concerns those conscious of having committed grave sin. Such a person should seek the Sacrament of Reconciliation before receiving communion. If this isn't possible, making an act of perfect contrition suffices so long as the person resolves to go to confession as soon as it is possible.
Frequency of reception is a concern for many older Catholics. Current rules are that as long as you receive during Mass, you can go to communion more than once daily. The only exception is in the instance of viaticum (literally, "on the way with you"). Someone in danger of death should receive communion outside the context of Mass even if they've already gone to Mass and received earlier that day.
The seventh regulation is the least well known. A Catholic may receive Eucharist from a non-Catholic minister in whose congregation Eucharist is valid when it's "physically or morally impossible" to do otherwise. Such occasions include danger of death or other "serious need"; persons who are "unable to approach their own minister"; "persons in prison or under persecution"; "persons who live at some distance from their own communion." The canon ends with the significant words: "this is not an exhaustive indication of such cases."
Scriptures: Mark 14:22-24; Matthew 5:23-24; 26:26-28; Luke 22:14-20; Acts 2:42-47; 1 Corinthians 10:16-17; 11:17-29; Revelation 19:9 // See also Canon Law 844, 912-923
Books: The Spirituality of Fasting: Rediscovering a Christian Practice, by Charles Murphy (Ave Maria Press, 2010)
101 Questions and Answers on the Eucharist, by Giles Dimock, O.P. (Paulist Press, 2006)