Here is a method I used when I got some Apps from the web....
Mount the SD card
Put the apk files on the SD card
UNMOUNT the SD card
Get ASTRO from the market place (as you suggested)
Open ASTRO
navigate to the apk files inside ASTRO
Click on the apk file
select install
IT WORKS LIKE A CHARM
ASTRO is a fantastic program and you can easily download it from the marketplace
The marketplace is the first point of call for now Apps or games etc its an icon on your phone showing a green Droid on a sort of carrier bag...... click on that and it gives you a list of things...... when you see what you want (say Astro ) just press or click on it again and it will give you a description and most of the time some screenshots so that you can see how good it is
Easy....
Pete
