The moment my brother 
After going through it myself, I realized that it is a complicated process if you haven't done it before. For people who don't have a Bitcoin savvy brother like myself to invest for them, a 'how-to' guide would be very useful. Here are the steps I went through. I hope you find them helpful!
To start with, here is the basic process: Step 1: Convert your money into Bitcoin. Step 2: Use your Bitcoins to buy Steem! (That's it!)
Here are the more detailed steps:
1. First you will need to signup for a website that allows you to buy Bitcoins. I personally used https://www.coinbase.com, because it has been around for a long time and is popular. If you don't have an account yet, it may take a couple of days to verify your identity before they will let you to make a purchase.
2. Once you are signed up for the Bitcoin purchasing website, login and purchase Bitcoins using the site's "Trade/Buy" interface. You can enter the amount in USD or in BTC.
3. After you have purchased your Bitcoins, login to Steemit.com, and open your wallet. Your wallet can be found by clicking on the "Wallet" link under your 'profile' picture icon. (It is in the upper right corner of the Steemit website.)
4. Inside your wallet, click on the drop-down next to "STEEM", and click the "Deposit" link.
5. Decide if you want to purchase "Steem" or "Steem Power".
6. The popup screen will have a "Wallet Address" near the bottom. This is where you will be sending the Bitcoins to make your purchase. The wallet address is the long series of letters and numbers, which is right after where it says "Send Bitcoin To". Copy this address to the clipboard. It is important that you copy the entire address, exactly as it is shown, without missing any of the letters.
7. Go back to the site you used to purchase the Bitcoins, and find the place where it lets you send Bitcoins. Enter in the wallet address that you copied from Steemit in the previous step. Enter the amount of Bitcoins you would like to send, and click the "Send" button to send them to your Steemit account. It will likely ask you to confirm. After that, you should see a success message showing the transaction was completed!
8. You will need to wait a little while for the Bitcoin transaction to confirm on the network. Most sites like Coinbase will show you the status of the transaction. Periodically check back and refresh. Once the transaction is confirmed, it will show up in your Steemit.com wallet!
That's it!
Thanks for taking the time to read this guide. I hope you found it useful! If you have any questions, please feel free to reply to the post.