I need to buy tubes and tires for a bike and I'm not sure what to get. This is my first time buying these and it will also be my first time installing them.

At this point my choices are Panacea, Cheng Shin, Pyramid, Kenda, Bell, and Schwinn. I'd prefer not to go with Bell and Schwinn for the tires as they cost twice as much as the other brands.

The bike is a child's bike that has 20x 1.75 tubes and tires. A young teenager will be riding it for recreational use on grass, dirt, pavement, and possibly rocks. The teen weighs about 150 pounds and might attempt a small stunt or two (mostly wheelies). It doesn't have hand brakes, just the pedal brakes. There are no shock absorbers at all.

Of the brands I listed, what are some good ones? Any bad ones?

If s/he will be riding where there is no glass, metal debris, etc (the main causes of flats) then almost any tire will work.
Are you installing the tires/tubes? Do you know how to do this and do you have the proper tools? I'm asking because I work in a bike shop and a few times a week someone brings in a wheel that they tried to install tire/tube without the proper tools and didn't know the correct way to mount the tire/tube.

If you don't have the tools or know the correct way, I'd suggest you go to a bike shop and ask them to show you how it's done.

I do not have any 20" tire bicycles in my family yet. My little one is too young. However, my Burley trailer has 20" Kenda Kwests. They seem to hold up well, but that is in a non breaking, non torque situation. I have had good luck with Kendas on my 26" and 700c tire bicycles though. Are you looking for longevity? If so Schwalbe may be the way to go, though they are of greater expense.

You should not have an issue with any of the brands listed. Although I will caveat that and say I only have personal experience with Kenda and Pyramid brands from your list. I have generally found tubes to be a low problem area. They valve works and they hold air fairly reliably. I would spend on the mid level tube or less. Also, with that said, I have run into some problem batches of tires, but only once. It is rare but it can happen. I'd recommend buying one tube of 2 or 3 brands. Mount the tire with the new tube and try it out. If the tire does not hold air, you will need to figure out why before blaming the tire which is what RonH writes about above. I.e. don't blame the tire when it could be user error.

Any of the brands you listed are decent for the price point. It depends on what kind of riding your teen does 90+% of the time and how far they plan to ride. Most standard duty tubes are pretty generic in terms of construction and quality...even the best/name brands sometimes have a bad batch that leaks or even blows up...lol...just have your teen carry a spare tube or a tube repair kit and a pump when they go out riding. Tire life varies regardless of how thick the tread is. But for most recreational riders, almost any tire will last for years with the occasional puncture.

Schwalbe Marathon Plus is probably out of your price range @~$35.00 a tire, but it is one of the best for puncture resistance.

Thorn resistant tubes are worth the slight extra cost. Most of the kids around my area use thorn resistant tubes on their 'stunt and dirt bikes'. The slight weight penalty isn't a big concern as long as they can ride to and from the local skate and bike park and do their stunts or jumps.

Tire and tube removal/installation is pretty easy, just need to buy a set of tire levers (only a few dollars for a set of 3) to make things easier (although some can do it by hand). Can read this link:
http://www.parktool.com/repair/readhowto.asp?id=100

All five brands listed are made by the same company. It's a junk bike. Just put the cheapest tires you can get on it.

All five brands listed are made by the same company. It's a junk bike. Just put the cheapest tires you can get on it.

The OP is about tubes not tires.

I am pretty sure the OP did not say it was a junk, inexpensive or an otherwise less than worthy bike. You can make an inference from the context but a pretty big leap to make that assumption on your part DD.

Even if it is a "junk" bike, I just did not see what you gained by potentially offending the poster. The OP came looking for help, not a beat down or public lashing. I would think you would not want to approach your customers in the same manner. My apologies if I misread your intent.

The OP is about tubes not tires.

I am pretty sure the OP did not say it was a junk, inexpensive or an otherwise less than worthy bike. You can make an inference from the context but a pretty big leap to make that assumption on your part DD.

Even if it is a "junk" bike, I just did not see what you gained by potentially offending the poster. The OP came looking for help, not a beat down or public lashing. I would think you would not want to approach your customers in the same manner. My apologies if I misread your intent.

The OP's first sentence says tubes and tires, then lists budget brands, then 20 x 1.75 tire size. You figure it out.