IF you've been counting off the days until Black Friday then, don't worry, it's nearly here.

Here's our guide to what you can expect this year.

When is it?

Black Friday is officially Friday, November 24 but some retailers have opted to start early and spread the discounts out over a longer time - up to a week beforehand.

What is it?

For those who have missed this in previous years, Black Friday started as in the US as the unofficial start of the Christmas season when shops slashed their prices in store and online for a single day. It was traditionally always the day after Thanksgiving - the last major holiday before Christmas and held on the fourth Thursday of November. In the UK, the idea has taken off in recent years and has become increasingly popular. It's also increasingly linked to Cyber Monday, usually the Monday after Black Friday which extends the sales for the weekend with the idea of encouraging people to shop online.

Sounds good, any downsides?

Yes. In the past, we've seen violence in shops as people fight over the best bargains or overcrowding with popular offers.

Police have already given advice to shops asking that they make sure they have enough staff and security to deal with any extra demand.

They say police officers should only be used as 'a last resort' and shops should have a visible security presence and make sure CCTV is being monitored.

Who is doing offers this year and when?

Dozens of stores and online retailers will take part including:

Currys - is doing a countdown to Black Friday - but has already got some discounted prices it calls Black Friday Prices available now

Amazon - will start its Black Friday deals from Thursday, November 16 and is running them until Sunday, November 26

Argos - plans to run Black Friday deals from Wednesday, November 15 for two weeks

John Lewis - the store says it will be constantly checking it is offering the cheapest price among its competitors even on Black Friday and will honour online prices in its High Street branches

Tesco Direct - has a 7-day Black Friday event planned starting online on Monday, November 20

Give me three top tips for bagging the best bargains

Shop around. Don't get swept up in the excitement and make sure you've done your homework so you know which discounts really are the bargains.

Be prepared. Pre-register with stores so you see the deals first.

Start early. If you really want a particular item, you will need to be early. Last year, queues at some stores started from the early hours of the morning.

Why is it called Black Friday?

The name appears to have come from the idea that the deals would help the shops go 'into the black' in their bank accounts.