iFixit is working on developing a solid yellow light of death repair kit and guides. We have successfully repaired PS3s using this method, and the kits should be available soon! It will certainly be cheaper than sending it elsewhere to get it fixed. I'll update this answer when our kits go public.

For iPod Minis, this usually means the incorrect/corrupt software is installed. This page will explain it further, and give you a link to download the iPod updater on your computer.

We actually have LCD screens available in the iFixit part store now! Check it out.

I assume your running Windows XP. If you have an Administrator account, it doesn't have a password by default. If you can log in as that, you can change your other user's password going to Control Panel/User. Select the account and select change password. If you don't have an admin account, shut down and restart. While the computer is booting, press F8 to enter the Boot menu and boot in safe mode. Select Run from the start menu and type control userpasswords2. Select the account and select reset option. Type a new password into new password and confirm and your done.

Please don't ask duplicate questions. A quick search shows many of this same question with good answers already. Heres a link to one.

Even with the device in rice, water can hang out inside the device for a long time. The water could have shorted out any number of things, and my first advice would be to open the iPod and thoroughly dry each component with a soft cleaning cloth. These guides will get you into the device. If iTunes doesn't read it after some thorough careful drying, I would bet the problem is a damaged logic board. We are currently out of stock on logic boards for the iPod classic, but you could asked to be notified next time we have them in stock here.

From the looks of that picture, you are going to need to replace the LCD. iPod Touch 3rd Generation Display Replacement

You may want to replace the thermal paste. The fan and heat sink can be removed with this guide. If your new to thermal paste installation, check out this.

Are you asking how to replace the screen or just telling us you broke it? If you need help with replacing your screen, we would need to know which iPhone you have. iFixit carries iPhone 3G Front Panel Kits and iPhone 3GS Front Panel Kits which have all the tools necessary for replacing those screens. We don't carry iPhone 4 parts yet, but they will be available soon. I hope this helps, but try to be more informative in future answer posts. This makes it easier to give you a useful answer.

It doesn't look like he is asking how to remove the battery. He is asking about charging the device. To answer your question, it doesn't matter either way. Whether you charge with a usb power adapter or with your computer, the device can be off or on.