I am not quite ready for this yet but would like to know the procedure(s) for:
1. User downloading my app from my website and installing it on a device
2. Installing app to the android market for $25 fee
3. Upgrading app on market( is there an additional fee?)
Installing an app to the market is very easy. Once registered as a developer you just log in and you will see a page that shows you a clickable button saying "upload application".
The market page you will see this option on when a registered developer will be
https://market.android.com/publish/Home
Just click that and it guides you through exactly what to do (you will need your compiled app on your computer and a couple of screen shots as you have to have at least two screen shots and the app itself to upload).
Basically you just click a button, locate the app on your computer and click upload. Same for your graphics. You also get a section on the same page to write about your app, this is the text that market visitors will see when they click on your app title while browsing the Android market, it tells potential users what the app does and anything else you want them to know.
The only fee is the one off $25, upgrading an app does not cost anything.
For commercial apps Google take a percentage (I think, I haven't put a commercial app on the market yet but I read the guidelines and I'm sure it specified a percentage).
As regards putting your app on your own site for download well its as simple as including a standard link in your web page to the apk file. However you need to be aware that if the users phone does not have the option to download non market sources they will be unable to install your app as a small number of devices come pre set to only accept apps from the Android market.
Dave