Amazingly informative. The only video I could find that covers all of the points of monetary system in CS.
It may not be that helpful since the CAS main server's every round start with 16k, but for people actually searching for 'guides' and not some 'pub pwnage tips', this video may help understand one of important aspects of competitive play.

n0thing's M4A1 guide

n0thing's AK47 guide

These videos wouldn't make you a world-class aimer just from watching, but they will certainly plant a seed for a future success in this area.
Quite clear and informative, it covers most of the aspects of handling these rifles.

Aiming in Shooters: The Right Side of the Brain

Visualizing Success

It’s up to you to decide if the information presented in these videos is helpful or not.

Counter-Strike 1.6: Tips and Secrets (part.1)

Counter-Strike 1.6: Tips and Secrets (part.2)

These videos assemble a lot of helpful information. Anyone watching them can learn something new and informative he didn’t know before.

CS1.6 – Angles & Positions

CS1.6 – Playing Against the Odds

CS1.6 - Boosting

CS1.6 - Ladders

The first two videos are quite informative and interesting, covering several aspects in both of them, while the later two covers very slim part of CS, but still being very informative.

Starting Competitive CS: ESEA

Well, this video explains what ESEA is. But it covers only positive aspects of ESEA.
As negative aspects, I can add that a lot of people care too much about their skill level and 'damage per round' ratio, so a lot of people tend to bait heavily just to get some extra kills. People care much more about it that they care about winning the round and game. So do not expect to have an amazing teamplay in pugs. The ESEA servers’ reg is also not the best possible. Compared to CAS Main server, it’s actually quite poor. Also that place is filled with childish, nooby admins. But, unless you can find a team in mIRC or in some pub, ESEA stays the only place where you can gain some experience in scrimming and teamplay, featuring quite skilled players to play against.

fRoD Offensive AWP guide

fRoD Defensive AWP guide

fRoD Bullet Management guide

The three videos above are not as informative as the ones in the beginning since the big majority of the tips presented in these videos covers mostly competitive playing and it's aspects. Pubstars wouldn't learn or need much of what was told there. But some of them might find the information presented useful.

Jonathan ''SwizzeR'' Menard's Channel
http://www.youtube.com/user/ProVideoGameStrats

This guy have a lot of videos that demonstrates the how to play different spots on several maps, videos explaining the difference between CS1.6 and CS: Source from his point of view, videos explaining how to make your own CS maps, and videos covering some other games, like TF2 and L4D. As you might have noticed, a lot of the links in this post are made to his videos.

By the way, he also have some technical PC stuff, anyhow related to gaming, like this one:
Ventrilo Guide