Its actually quite easy. I opened an account with coinbase. Just follow the stages setting it up, ie mobile phone number etc, give them a copy of your ID, drivers licence/passport etc (was best to click on the phone option and send them a photo) and within 5 minutes your set up and ready to buy and its an easy to understand layout, just put the amount you want to spend and the currency (ie bitcoin) you want to buy, it shows a total with small fees and purchase the crypto buggers.

I initially spent £35 and got just over 0.01 bitcoin and on steemit you just go to "wallet" "buy steem" and on blocktades click on "get new deposit address" and copy and paste the long number above the square into coinbase (or other provider) and send.