So you made it. After living a monastic life in your room for two years, you can now emerge into the light with that precious CAO offer notice trembling in your hand.

This means the end of school, homework, parent-teacher meetings, double maths on a Friday afternoon and that annoying classmate who has been dogging your steps since you were in junior infants.

So, much cause for euphoria.

But having come this far, it would be a shame if you made a mistake in the offer period which cost you that precious place. So tread carefully and observe some basic rules.

If the offer notice arrived in the post, examine it closely. Make sure the notice includes your application number. Carefully read the course or courses you have been offered. Double-check them in the main CAO handbook if you are unsure.

Many of you will have received two offers - one from the degree list and one from the certificate/diploma list.

It may seem obvious, but make sure you only send back one offer. A CAO spokesman told us each year they get a significant number of students sending back both offers.

If that happens, the CAO will choose one for you. They will not contact you to tell you there is a mistake and in practice they choose the degree. That is fine if it is the one you want, but if you had your heart set on a certain certificate or diploma course it could be a disaster.

When you send off the offer notice, get the post office to stamp the certificate of posting in the CAO handbook or write you a receipt. The reply date this year is August 29th at 5.15 p.m. and there is no leeway on this.

The CAO will send you confirmation within three days that they have received your offer notice. If you do not receive confirmation within three to five days, contact the CAO immediately.

Presuming there are no problems, your new college will send you separate material and registration details.

While the CAO process is free (except for postage) your college reserves the right to charge you a registration fee or student-facilities levy.

Of course, you can cut paper out of the process completely by accepting your offer online at www.cao.ie.

This can be done from this morning and all you need is your CAO number, a computer and a printer.

Key in this number and your date of birth and follow the instructions.

Make sure you get a receipt at the end of the process - if you don't, it means the CAO has not received your acceptance properly.

The online option is open until August 29th at 5.15 p.m.

Many students contact The Irish Times each year to ask if they can change their choice at this stage. Many will be students who put at the top of their list something they later regretted. No, they cannot change now.

Other students get an offer down their list and wonder about taking it. Accepting an offer at this stage does not rule you out for further offers, so what you can do is accept this offer now and hope another comes up in later rounds.

The advice is the same every year - you can go up the CAO list, but you cannot go down.

Some will be happy with your offer but may not want to enter college straight away, between 5 and 10 per cent of places are deferred each year. If you want to defer, do not accept the offer in the normal way.

Instead, write to the admissions officer at the college concerned and attach the relevant part of the offer notice. This letter must arrive by August 27th.

The college will then write to you telling you whether the request has been accepted. If it is not, which would be quite unusual, you can still accept the offer for the current year.

The second round of offers is due on Tuesday, September 4th and the reply date for this round is Monday, September 10th. Offers will continue until October 17th.

The CAO can be contacted on 091-509800