Trouble migrating from Yum to apt-get

About your requirements, Iceweasel is the supported Firefox derivative (fork), I'm currently running debian as my desktop OS at work and use iceweasel every day, no problem. Gnome3, I think it'll be available on the next stable release, BTW what release are you running? Squeeze? If so I think (IIRC) Wheezy will have it. And finally, about graphics performance/quality, that depends a lot on your graphics card and its driver, but if you think of it like having transparencies, windows closing with fancy effects and so on, you'll need a moderm desktop or compiz (work with gnome2) which I think its available on stable (wheeze).

I have modified a bit your sources.list for wheeze, do you mind to test it and report back?

deb http://http.us.debian.org/debian/ squeeze contrib non-free main
deb-src http://http.us.debian.org/debian/ squeeze main

deb http://security.debian.org/ squeeze/updates main non-free contrib
deb-src http://http.us.debian.org/debian/ squeeze/updates main

# squeeze-updates, previously known as 'volatile'
deb http://mirror.cse.iitk.ac.in/debian/ squeeze-updates main non-free contrib
deb-src http://mirror.cse.iitk.ac.in/debian/ squeeze-updates main non-free contrib

# 3rd party repositories
deb http://packages.dotdeb.org squeeze all
deb-src http://packages.dotdeb.org squeeze all
deb http://www.deb-multimedia.org squeeze main non-free

If you happen to be using wheezy or sid you'll have to change all squeeze ocurrences for the one you're using.

Please, backup your sources.list before replacing it, then test it as follows:

Refresh caches

# apt-get update

Search package

# apt-cache vlc

Install package

# apt-get install <package_name>

If find trouble, please report back with output for those three commands, or at least for the first and last.

Also, if you are already using Wheezy or sid, forget what I said about Gnome3 not being available, it should be there but wheezy is yet to be release and sid is always the development branch.

One thing to keep in mind if you're used to Yum is that the list of available packages is not updated automatically, so you must run apt-get update whenever the package sources change, and periodically to keep it up-to-date.

apt-get does handle dependencies. (That's where Yellowdog and Red Hat got the idea.)

I don't know precisely what caused the error you saw, but there are two common causes for this error message:

• You modified the list of sources but did not run apt-get update, or apt-get update ran partially but some index files could not be downloaded. Remedy: run apt-get update.
• You're installing packages from a broken source. The unstable release (codename sid) always contains the latest version of packages, and if the dependencies aren't in yet, too bad. Remedy: use the testing release, which is generally behind unstable by a few weeks and is consistent with respect to dependencies. Or use the stable release which is a bit like Red Hat to testing's Fedora (at this time, squeeze is the stable release, and wheezy is testing).

With respect to your sources, I recommend starting with only Debian official sources, and then adding third-party repositories such as Dotdeb and Debian-multimedia only if you actually need them.

apt-get handles package installations. To query the database of available packages, use apt-cache: apt-cache search part_of_package_name_or_description.

You may prefer to use aptitude, which combines the functions of apt-get and apt-cache and has a text mode interactive interface as well.

Iceweasel is exactly Firefox except for the name and logo. Debian doesn't distribute Firefox under the Firefox brand because they don't have the permission. VLC and Gnome 3 are in the standard Debian distribution.