I found this important because many of my friends say that downloading packages is a big problem as they do not have access to internet.
Although there are many ways to get your packages offline, like:
1. Take Synaptic package manager, Mark all the packages you need (the dependencies will be automatically marked)
2. Go to File -> Save Markings. Save it (script)to an external medium like USB flash drive.
3. Take the pendrive to system where u have internet connection and Linux installed(hard drive/virtual)
4. Run the script as
This will do it and store the packages in USB drive. Install it by using the command
sudo dpkg -i -force-depends *.deb
alternatively you can open the script and download files using IDM.