Максим

...
render()
...
  if (this.props.isFetching) {
    <p> Loading...</p>
  } else {
    <p> {ВАШИ_ДАННЫЕ} </p>
  }

А то решений сейчас много и не знаю какое выбрать

...
<Route path='/signin/:название_параметра' component={Компонент} />
...

const mapDispatchToProps = (dispatch) => ({
  fetchEntities: (limit, offset) => dispatch(fetchEntities(limit, offset))
})

...
router.post('/', (req, res) => {
    const {errors, isValid} = validateInput(req.body);

    if(!isValid) {
        return res.status(400).json(errors);
    } else {
        return res.status(200).json({data: 'bla-bla-bla'})
    }
});
...

axios.post('/user', {
    firstName: 'Fred',
    lastName: 'Flintstone'
  })
  .then(function (response) {
    console.log(response);
  })
  .catch(function (error) {
    console.log(error);
  });

import * as UserActions from '../actions/UserActions'
...
const mapDispatchToProps = (dispatch) => {
  return {
    userActions: bindActionCreators(UserActions, dispatch)
  }
}

const mapDispatchToProps = (dispatch) => ({
  userActions: bindActionCreators(UserActions, dispatch)
})

import { AppContainer } from 'react-hot-loader'
import React from 'react'
import ReactDOM from 'react-dom'
import { Router, browserHistory } from 'react-router' // раз
import { Provider } from 'react-redux'
import { routes } from './routes'
import { syncHistoryWithStore } from 'react-router-redux' //два
import configureStore from './store/configureStore'

const store = configureStore()

const history = syncHistoryWithStore(browserHistory, store) //три
const rootEl = document.getElementById('root')

ReactDOM.render(
  <Provider store={store}>
    <AppContainer>
      <Router history={history} routes={routes} /> //четыре
    </AppContainer>
  </Provider>,
  rootEl
)

import { routerMiddleware } from 'react-router-redux' //раз
import { browserHistory } from 'react-router' //два
import { createStore, applyMiddleware, compose } from 'redux'
import thunkMiddleware from 'redux-thunk'
import createLogger from 'redux-logger'
import { rootReducer } from '../reducers'

export default function configureStore() {
  const store = compose(
    applyMiddleware(thunkMiddleware),
    applyMiddleware(createLogger()),
    applyMiddleware(routerMiddleware(browserHistory)), //три (!)
  )(createStore)(rootReducer)

  if (module.hot) {
    // Enable Webpack hot module replacement for reducers
    module.hot.accept('../reducers', () => {
      const nextRootReducer = require('../reducers').rootReducer
      store.replaceReducer(nextRootReducer)
    });
  }

  return store
}

import { combineReducers } from 'redux'
import { routerReducer } from 'react-router-redux' //раз
import products from './products'
import login from './login'
import notificationBar from './notificationBar'
import provider from './provider'

export const rootReducer = combineReducers({
  products,
  login,
  notificationBar,
  provider,
  routing: routerReducer, //два
})