A good starting point would be to review the minimum and recommended specifications for Skyrim.
http://www.tomshardware.com/news/Elder-Scrolls-Skyrim-System-Requirements-Pete-Hines-RPG,13821.html
Next, you need to come up with a budget and what components you need (for instance, do you need to buy a monitor, or do you already have one?).
Are you planning to run high resolution textures, either the Bethesda ones or ones added by mods? If so, you're going to need a graphics card that's better than the recommended one.
These need to be answered, the budget one especially, before anyone can make any good recommendations.