This is a HUGE question, which a book could be written on.
It's not just about prayers, though piety is very important. In fact, he who does not pray will not save his soul. That is not my opinion, but rather is what all the saints tell us. The Rosary is a good minimum to start out with. You can say it throughout the day if you're extremely busy. But the fact is, you make time for what you care about. If you REALLY WANTED to say the Rosary every day, you would find the time. You can say it while driving, for instance (though it's not the best time -- you can be very distracted on the road).
You have to make the faith the center of your life -- why you chose the house/car/job/school you did, who you hang out with, how much you spend, what you eat, how you spend your time, how you decorate your house, etc.
All of those things should be chosen based on a prayerful, "What does God want me to do?" God's will is manifest in many ways, but usually in the voice of one's parents or superiors. If you are an adult, then it is usually manifest by the circuмstances you are placed. Sometimes it's hard to discern, but that's what meditation and prayer is for.
To see what it REALLY means to be Catholic, I suggest reading some books about the saints' lives. There are hundreds and thousands of saints to read about -- some we know very little about (the early martyrs, for example) but many are very well-docuмented. There are large books about some of the saints, and I strongly suggest you check them out. (
http://www.chantcd.com/books.htm) They came from all walks of life, and were all races, shapes and sizes. Several saints had a lot in common with you -- I can say that with a fair degree of certainty. But you can see how they lived their life in a Catholic way. For the saint, going to Mass is a logical extension of the rest of his life. There should be no "jarring" or "dual-life" switching back and forth from "Catholic" to "fits in with the world" like an old manual car that needs transmission work.
Saturday: That car is awe-SOME! I can't wait to get a car like that. Hey can we stop at Best Buy a sec? ..... Hey what movie you guys wanna watch tonight?
CLUNK!
Sunday: In nomine Patris, et Filii, et Spiritui Sancti. Amen. (opens missal to the 17th Sunday after Pentecost...)
CLUNK, CLUNK!
Monday: (phone rings) "Hey man, what's up! Yeah, she's pretty hot isn't she. Hey I'll be over in a few minutes -- sounds like fun!" (and then proceed to a party, which uses up the remaining free time in the day, preventing you from saying the Rosary, doing any spiritual reading, etc...)
I think I made my point
Above all, we must cast off the world if we are going to build up a Catholic life in its place. The world around us today is completely incompatible with the Catholic way of life. That is why I don't have a TV set. The TV puts forth the spirit of the world, which is as opposed to the spirit of Christ as the devil is opposed to Christ. The TV also causes much waste of time that God gave us. Every minute will have to be accounted for at the judgement. I waste plenty of time on the Internet without having a TV set to tempt me with lazy, passive entertainment. It's like junk food -- you never REALLY develop a strong distaste for it. As long as you're human, it will appeal to your lower nature.
We need to shut out the constant noise from our soul -- we need quiet and concentration sometimes, so that we CAN pray. I don't think we need so many music-playing devices (home stereo, car stereo, iPod, cell phone, computer, etc.) -- when are we supposed to be alone with our conscience, able to think about God and eternal things?
Same for visual noise -- get rid of as much advertising exposure as possible (another good reason to get rid of the TV). Throw away the newspaper ads, don't pay for shirts that are basically advertisements (they should pay YOU!), stop shopping just for fun, etc. Instead, fill your house with sacred artwork, crucifixes, and things to remind you of what you CAN'T see around you -- the Blessed Virgin, heaven, the last judgment, the saints who have won heaven, etc.
Matthew