@gary4gar oracle will run on linux but you will need to download linux version of oracle. Do not run windows apps on linux as far as possible as it can laed to improper functioning of programs.
For practising VB6 you can try gambas which is very similar or there are other alternatives for VB in linux. For, .net you have mono project in linux.
If you don't want to download much, you can order debian cd's/dvd's. Debian is a set of 14 CD's /3 DVD's and will contain almost everything you need and more. But, I am not so sure if it will have a few apps like oracle. But, debian is a really good distro and with 14 CD's you will have your hands full to explore without having to download much softwares.
Or you can buy May or June's Linux For You. It will cost Rs. 125 but it's worth it. You will get Fedora Core 5 with May's edition and Suse 10.1 with June's edition besides there will be some nice articles in the magazine to read about.
As far as hardware goes, I don't think it will have any problems with any recent distros. I don't know about your router but if it is connected through lan card it won't be a problem.
To learn basics of linux go to
The Linux Documentation Project Guides. You will get plenty of resources there. Also
Ubuntu Guide is a good place if you are using ubuntu.
Even in linux yu will have to install some security related softwares but they are free. Even though linux is more secure it is not completely secure, in fact no software can be completely secure. So, you need to have a few security softwares installed and configured.
About usage of resources, do not use KDE because you lack a little bit in RAM, so the performance will be sluggish. rather use some window manager like XFCE and your machine will run really fast.
@ nitish
Your problem with compiling the drivers lie with your version of GCC, I think you will need GCC 3.x. Some user of FC will be able to point out to you where to get GCC 3.x from, I don't have much idea.
I am asing for the README file that is contained inside the network driver's archive. That mioght help in knowing what version of GCC might be needed.
You need to download rpm's for FC5. All RPM's will work, but the RPM's specific to FC5 will work better and cause less dependacy problems, but still it might have one or two dependancies which might need to be downloaded.