What is bitcoin? Google defines it as follows: "a type of digital currency in which encryption techniques are used to regulate the generation of units of currency and verify the transfer of funds, operating independently of a central bank." My understanding is that this definition is true of most any CryptoCurrency.
Informative article by CNN - http://money.cnn.com/infographic/technology/what-is-bitcoin/
Where can I spend bitcoins besides treating it like a stock? https://support.coinbase.com/customer/portal/articles/1834716-where-can-i-spend-bitcoins-
The place to check the value of each coin ranked from largest market cap to smallest: https://coinmarketcap.com/ This website allows you to look at the price movement in any coin you click on for 1 day, 1 week, 1 month, 1 year, or all time. Price movement is shown in USD, Bitcoin, and Total Market Cap. Also shows trading volume.
The coin I have been mining is called Ethereum. The website I use (https://www.genesis-mining.com) allows mining of Ethereum and Monero, I find Ethereum more lucrative. Ethereum mining has no fees (many other coins have fees). Also Ethereum mining recently became profitable as the price increased so pay attention to the date on any posts saying that it isn't profitable. If you want to start mining with genesis-mining.com then you can get 3% off by using my promo code: 9iEgeW
A website for calculating your return http://www.coinwarz.com/calculators/ethereum-mining-calculator
Notes for the calculator:
1 MH/s of mining power for Ethereum costs $30 (slightly less if you invest more)
The power cost is $0 (this is something to consider only if you are using your own hardware)
The price fluctuates like a stock. You can look at the graph for Ethereum on coin market cap.
The difficulty increases as more people mine (this makes it take longer to mine 1 Ethereum, but this often correlates with price increases)
What is Ethereum? It is the 'coin' with the second highest market cap as seen on coin market cap. An article about its rise by bloomberg: https://www.bloomberg.com/news/articles/2017-05-31/bitcoin-risks-being-eclipsed-by-digital-coin-cousin-ethereum
Also worth noting, you could invest in the CryptoCurrency market without getting involved in mining and without getting involved in Ethereum. Each coin has differences in functionality, and some are part of unique platforms.
Feel free to ask questions in the comments and I will do my best to provide answers.
Cheers!
techguyjoe