Press your lips together, add vocal cord vibration, then release.

Americans pronounce bookshelf as BUUK-shehlf (/ˈbʊkˌʃɛlf/). The L in "bookshelf" is a dark L — the back of the tongue rises toward the soft palate, adding a small "uh" quality before the L. This is called the Dark L vs Light L, a small move that separates 'classroom' from 'native'. It comes out as BUUK·SHEHLF. Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "He assembled the bookshelf without reading the instructions".
Record yourself saying "bookshelf" and play it back. The mic stays on your device — nothing's uploaded.
2 syllables, 7 sounds. Tap a syllable to jump to its row, then explore each sound's mouth shape and how it's made.
Press your lips together, add vocal cord vibration, then release.

Bring the corners of your lips in slightly so they push forward, but keep them relaxed. Lift the back of your tongue toward the roof of the mouth.

Raise the back of your tongue to touch the soft palate (velum). Stop the air, then release.

Flare your lips and lift the mid-front tongue close to the roof of your mouth. Blow air through without voicing.

Drop your jaw moderately. Touch the tongue tip behind the bottom front teeth and lift the mid-front part slightly toward the roof.

Keep the tongue tip down and pull the back of the tongue up toward the throat. The 'dark' sound comes from the back.

Lift your bottom lip to touch the very bottom of your top front teeth. Blow air through this contact point without voicing.

The textbook way isn't wrong — it's just not how anyone actually says it.
The L in "bookshelf" is a dark L — the back of the tongue rises toward the soft palate, adding a small "uh" quality before the L. Dark L adds a small schwa-like "uh" before the L. The back of the tongue lifts toward the soft palate.
In "bookshelf", the "k" is not released — the articulators get into position but hold without the burst of air. Air stops but there's no release burst — the articulators hold position.
Stress falls on the first syllable, not the others. Stretch BUUK — keep everything else short and quick.