How can I console.log the value of a observable?

The quickest way to add logging is to put .pipe(tap(console.log)) after your observable (in this case after this.store.select<any>(state => state.count)). If you have to log observables often, you're better off with a logging utility. I've written one such utility 1log:

import { log } from '1log';
import { timer } from 'rxjs';

timer(500).pipe(log).subscribe();

With a regular observable you only get the value when it changes, so if you want to console.log out the value you will need to console.log it in the subscription:

constructor(
    private store: Store<any>
  ) {
    this.count = this.store.select<any>(state => state.count);
    this.count.subscribe(res => console.log(res));
  }

However if you are wanting to be able to get the current value at any time what you will be wanting is a BehaviorSubject (which combines an Observable and an Observer in function...import it from the rxjs library like you do Observable).

private count:BehaviorSubject<number> = new BehaviorSubject<number>(0);

constructor(
    private store: Store<any>
  ) {
    let self = this;
    self.store.select<any>(state => self.count.next(state.count));
  }

Then any time you want to get the current value of the count you would call this.count.getValue() to change the value you would call this.count.next(<the value you want to pass in>). That should get you what you are looking for.

With recent versions of RxJS (AFAIR starting from 6.0) the proper way is to use .pipe(). And to answer to your question you need tap operator.

constructor(
    private store: Store<any>
  ) {
    this.count = this.store.select<any>(state => state.count).pipe(
        tap(countValue => console.log('Count: ', countValue))
    );
  }