How is it that websites like SCG or CFB created their card database inventory. How would i be able to do this myself now? I want to create a similar website where a user can search and find any card with images. Obviously entering manually into a sql server is not feasible. Any help on easiest way to get this done?
There's a program called Gatherer Extractor which can extract all info and images from Gatherer. You can export it to an XML file which you can import easily into (eg) a MySQL database.
You can check the sets which you want to download, and the info you want.
I may be wrong, but I am pretty sure magic.tcgplayer.com offer a crystal commerce solution to the stores selling cards through their platform. This includes a card database which is updated by them (an advantage if you are lazy, can be a disadvantage if you want to take advantage of the pre-order market).
I believe they only offer this to US based stores, so outside of the US you might not be able to make this work for you, inside however its a very easy set up which works well on mobile devices as well as regular browsers, and can be customized quite significantly.
This may not suit your needs personal, but others looking to start a new online magic singles store may well want to go down this route.