However, I don't recommend beginning with bottleneck, even though it's a simple enough form. Youtube has many basic lessons for playing slide and bottleneck. A basic blues in the key of E has many advantages. For one thing, three basic chords, E, A and B7 gives a splendid basis for learning the blues style. Don't use fancy inversions, but stick to the basic chords for starters. Just strumming the E chord on a guitar with powerful basses immediately puts us in the mood!
Many players use the monotonic thumb style of playing, where the thumb strikes the bass E regularly, providing a lovely drone sound but also can be a drum sound. Yes, even with such a basic strike, there are nuances and things to learn. For example, if you hit the Bass e string with your thumb and let it ring, the sound will sustain and provided counterpoint to any treble work your fingers might play.
On the other hand, if you drop the palm of your hand onto the string just after you hit it, the sound will be clipped or damped, choked off. it sounds like a drum and musicians such as Mance Lipscombe, Lightnin' Hopkins and Big Bill Broonzy used this to great effect;
In my own courses, I recommend two songs by Hopkins - Baby Please Don't Go and Mary to start off with. They are both in E and use the monotonic bass thumb technique, but the pace and approach is different. In some places Hopkins lets the bass E ring out (particularly when he's laying down a riff on the treble strings high up the fret board) and sometimes he damps the bass strings in a percussive manner, laying down a beat. He also doubles up on the tempo, producing what he called a heartbeat effect, which had a powerful pull on the emotions of his audience.
