Money
As Homer's brain once told Homer money can be exchanged for goods and services. And examples of goods and services include food, roof over your head, clothes, books and drink. So it's kinda important.

It's a good idea to get your head around information like how much your rent is, and how much you are spending on food and/or going out. Then you can checking this against how much money you have coming in. Hopefully then the two balance out.

If not, and you find yourself in money problems don’t panic. Or spend your last five euro on lottery tickets. If you are in over your head seek advice. Your students union will either advise you or put you in touch with people who can.

Banks
Banks offer a wide variety of services to new students. The idea is they give you stuff now and you give them stuff [like say a mortgage] when you're older and richer. Opening an account is a very simple procedure. All that is required is a formal means of identification, and a few signatures later a new bank account is thine.

Campus branches tend to be very familiar with students and student lifestyles so they should understand and appreciate your situation. Freshers' accounts also tend to come with plenty of cool free stuff. There is no law against taking advantage of as many banks as you can. There is a law that says you have to pay tax on ATM cards though so be careful. You shouldn't have to pay bank charges if you have a designated student account.

Loans
Lots of students take out loans. The problem with a loan is that it has to be paid back. The beauty of a loan is that you can pay it back later, when you [hopefully] can. Campus banks tend to have dedicated students' officers who's job it is to be sympathetic and understanding to poor students. In a lot of cases, the bank will not give a loan to someone who has no credit history without a guarantee from another person. Often that other person must be a householder. Which generally means asking a parent or close relative to act as guarantor.

Overdrafts
An overdraft is like a short term loan. The bank allow your account go into debt up to the amount of the overdraft, which you agree to clear by a specified time. This time is generally shorter than that of a loan, and the interest is generally higher.

Grants
The student grant may not be adequate in Ireland, but it is still invaluable for many students. The eligibility requirements are complex, but well worth sorting through. All the relevant information is on the government site through here. For more information contact your local authority.