Thanks, I am not really a gamer so I don't know when deals hit. I will check out Steam on Thursday.
No problem. Since you're going to check out Steam's holiday sale, there are a couple things to keep in mind.
During major Steam sales, they have special "daily" deals, where games that are already on sale get an even deeper discount. You might see a 50% off game going to 75% off.
In addition, they've also had 8 hour deals of the same deeper discount. These 8 hour deals, if Steam has them again this time, offer the same discount you'd find on a daily deal.
With the above in mind, the best thing to do, if you're looking for a particular game, is to check once a day after the new deals show up (1PM ET).
The golden rule of Steam sales is don't buy a game you have your eye on until the end of the sale in case it gets one of the aforementioned deeper discounts.
Now, since I'm guessing you plan on buying these as Christmas gifts, you probably can't wait all the way to the end of the sale to see if a better deal pops up, but it's still something to keep in mind. You could keep checking daily until Christmas Eve and then make your purchases.