This is not a good guide, sorry. The route through Coinbase/Bittrex/Whatever else centralized exchange is expensive, slow, and actually risky. Bittrex? Come on. They disable accounts for verification which takes months, and then they “leak” gathered passport data to hackers. Withdrawing from Coinbase or Bittrex will also take days if not more.
Basically, what has to be mentioned is the general principle: the way to get into altcoins is to buy Bitcoin and then exchange it using dozens of services (Altcoin.io, Shapeshift, Changelly, Bisq etc.). That’s it.
Plus there’s the ultra-convenient 3-click credit card purchase of pretty much any altcoin you need at Changelly (reflink, but to an actually useful service).
Had to put together an altcoin purchase guide that packs better advice, to make sure newcomers don’t get stuck with coinbases and bittrexes: http://coinvigilance.com/how-to-buy-altcoins-the-simplest-guide-online/