There are three working modes: Fast Sync: By default, the first time you run geth command is in this mode Full Sync: If the geth process has been interruped. An re-issue of geth command will be in this mode Light Sync: A less secure way with header only Download link: https://ethereum.github.io/go-ethereum/downloads/

On Mac, set the PATH for geth

echo 'export PATH=YOUR_PATH_TO_GETH_FILE:$PATH' >> ~/.bash_profile

To run the geth process in Fast Sync Mode

./geth

To run the process in Full Sync Mode Type Command-C to stop the process.

• Delete the directory 'geth' under /Users/YOUR_USER_NAME_ON_MAC/Library/Ethereum
• Run the geth command again

Connect to the Ethereum node

./geth attach ipc:/Users/YOUR_USER_NAME_ON_MAC/Library/Ethereum/geth.ipc

Create new account

> personal.newAccount();

Example result

Passphrase: 
Repeat passphrase: 
“0x32a28e00186612638d91ce7aad6c832ae56c2a9e"

Synchronize blockchain node

> eth.syncing

Example result

{
  currentBlock: 180885,
  highestBlock: 4930769,
  knownStates: 207716,
  pulledStates: 197461,
  startingBlock: 0
}

https://github.com/ethereum/go-ethereum/wiki/Management-APIs

Initialize with gensis.json

{
  "difficulty" : "0x20000",
  "extraData"  : "",
  "gasLimit"   : "0x8000000",
  "alloc": {},
  "config": {
        "chainId": 15,
        "homesteadBlock": 0,
        "eip155Block": 0,
        "eip158Block": 0
    }
}

> geth init ./genesis.json --datadir my-chain-data

To start the network

> geth --datadir my-chain-data --nodiscover

Launch a Geth Javascript Console to interact with the node

> geth attach ipc:/YOUR_IPC_END_POINT/geth.ipc

In the javascript console, show current accounts by

> eth.accounts

To create new account

> personal.newAccount()

The private key of the new account is stored in keystore folder

Set the account

> miner.setEtherbase(eth.accounts[0])

Run the miner

> miner.start(1)

Checkt the ether

> eth.getBalance(eth.accounts[0])

geth --datadir my-chain-data/ --nodiscover --unlock 0 --mine 1