Your advice for PC/Laptop hardware

Since the majority of World Design has the income to buy/upgrade their machines,
to high specs without the fear of accidently breaking it and buying it again. I was wondering maybe you lot's can give advice to newbies with minimum of IT experience on what to look out for in computer hardwares - stuff like overclocking and what's good or not in graphic card especially the brand. Terminologies and so on. Newbie's guide to advance stuff would be cool.

Please be detailed and simple and please provide links. I been struggling to find guides that are aimed at intermediate level on explaining the whole lot. Most of them are very advance and "heavy jargon" to a point -that to anyone who has never had experience in that particular field would be like... wha? So please help out.