Steam Sales

Major ones are Summer and Winter sales. A couple of times there's gonna be some smaller ones like last year's spring sale but those are rarer.

Buy them games on winter sales since you'll have to wait a few months to waste more monies.

There's the summer sale, which is usually around mid-June. Other than that... No major ones that I can think of.

Halloween is usually specialized for horror games and Winter sale has a lot more titles available on discount. Winter sale will usually see the same kinds of discounts as the Summer sale tends to get. I think Steam also has sales for Black Friday.

There may or may not be a Black Friday sale in November, depending on how they feel. They are likely to have special Steam anniversary sales on special anniversary years, as well.

But anymore, the Summer/Winter sales don't offer greater discounts than the weekly sales, there's just a lot more on sale all at once. In fact, for many titles now, the discount offered when they go on weekly is often slightly better than it will be during the Summer/Winter now. Why? Because they know everyone and their cat is shopping on Steam during the Summer/Winter, so they know they can safely eke out a few more percentages during those sales what with everyone already herded into the store ready to shop. In short, if you see it on deep discount, it's safe to buy it whenever you see it.

Another thing I wanted to know if the money I would have in wallet would be enough for a good amount of games (not indie ones)?

For non-indies, the discount range is based on release and sales history. So, depending on how strong sales have been,:
Recent releases: 10%-33%
Slightly more stale: 50%-66%
Past it: 75%

"Staleness" usually sets in at 6 month to a year after release, but this varies widely by popularity. "Past it" occurs generally around the 2 year mark, but depends heavily on the game's sales.

How much you can buy will then depend on where your interest lies within those price ranges.

I would definitely go with the winter sale. Mostly because it's sooner and I know how bad it is to have game money and not wanting to spend it.

Well just as a piece of advice the major sales has two levels of discount:

the general sale price (lasts until the end of the sale)
And the Daily/Flash/etc discount (higher than the other one, but for a much more limited time)

Anotehr is that when a game goes on a featured sale, other related games may get extra discounts as a result. A semi-recent example was when Ground Zeros got a featured sale, Revengence also got a pretty nice discount.

And you should try to wait for a featured sale before springing for it.

Stabbing yourself is difficult. Let me stab you so I can loot your Steam Wallet.