zebedee1691 has provided the most succinct answer. Excess alcohol carries a mandatory 12 month disqualification for a first offence (36 months for a second offence within ten years of the first). This period increases as the level of alcohol increases.
Apart from the ban offenders can expect to be either fined, awarded community penalties or even receive a custodial sentence of up to 6 months. Again this depends on the level of alcohol detected. Custody is considered when the alcohol reading exceeds 115micrograms of alcohol in 100ml of breath.
Disqualification periods can be reduced by 25% if the offender completes (and pays for) a drink-drivers� rehabilitation course. This is almost always offered to first time offenders.
The only aspect of the answers given so far which is incorrect is the issue of new drivers� licence revocation. When a new driver (i.e. one who has passed his test less than two years ago) is disqualified, revocation of his full licence does not follow. It only follows when the driver accumulates 6 or more penalty points within the two year period. Disqualification does not attract penalty points (the two are mutually exclusive).
This is an anomaly in sentencing procedures and often leads to new drivers who are convicted of offences which would normally take them over five points asking the court to impose a short disqualification instead of points. This enables them to retain their full licence after the disqualification period has elapsed.