I wouldn't want to store btc anywhere online.

What's meant by the "blockchain loading up"?

How I am I supposed to know about encrypting wallets, backing up dat files etc.

I'd thought that these were relatively simple questions I'd asked in my first post, and had hoped for relatively straightforward solutions. At this rate it's going to be many years before btc gets anywhere remotely near to mainstream acceptance. Not a reflection on the person who replied, but this reply has swayed me slightly more towards deciding against btc than I was before. 

I'm undecided as to whether or not to buy into BTC, both pro and anti arguments seem equally persuasive to me. However if I do decide to buy btc there are some basic questions I'd need answered first by someone with btc experience/knowledge because I'm somewhat tech challenged and don't personally know anyone who knows anything about bitcoin.

First if I bought btc I wouldn't want to store it on an exchange like MtGox or whatever I'd want it secured on a thumb drive and off my computer. How do I go about doing that? I've never even bought or used a thumb drive before. So question 1 is how do I safely and securely download a wallet, buy bitcoin then transfer it to and securely store it on a thumb drive? (I'm using Windows 7). Also how would I actually pay for it, I'd have to withdraw from my bank account, right? How is that done? And how could that make it "anonymous"?

2nd question : if I had btc then if/when I want to sell it for GBP or USD, presumably using the thumb drive, then how would I go about doing that safely and securely?

Any help/information in lay terms gratefully appreciated.