7 steps. Let's go.
6 faces, each a different colour. The centre piece on each face never moves.
Key idea: Centres never move. If the centre is red, that whole face needs to be red.
Each face is named by where it is when you hold the cube:
Each move = which face + which direction. Prime (') = opposite direction.
Find the white centre. Hold it on top. Build a plus sign (+) of white edges around it. Each edge must match the side colour too.
3D view: top + front + right
No algorithm. Move white edges to the top, matching side colours.
If a white edge is on top but the side colour is wrong: do Front, Front to push it down, turn the bottom to move it aside, then try again.
Fill in the 4 corners to complete the white face. Find a white corner on the bottom layer, position it below its target spot, then repeat:
Corner in the wrong spot on top? Do this algorithm once to knock it to the bottom, then solve it.
Flip the cube. White on bottom, yellow on top. Keep it this way from now on.
Goal: fill in the 4 middle-layer edges. These are edges with no yellow.
Find a non-yellow edge on top. The colour facing you tells you which face it belongs to. The colour on top tells you which direction to insert it.
Top colour matches the right side's centre. Line up the edge's front sticker with the front centre first.
Up, Right, Up', Right', Up', Front', Up, Front
Top colour matches the left side's centre. Line up the edge's front sticker with the front centre first.
Up', Left', Up, Left, Up, Front, Up', Front'
Edge stuck in the middle layer but wrong? Do either algorithm once to pop it out, then re-insert correctly.
Make a yellow plus sign (+) on top. Ignore corners for now.
Front, Right, Up, Right', Up', Front'
The yellow cross is done, but the side colours of those edges may not match their centres.
Right, Up, Right', Up, Right, Up, Up, Right'
Get each corner to the right spot. They may still be twisted wrong; that's fine.
Up, Right, Up', Left', Up, Right', Up', Left
Corners are in place but some have yellow facing the wrong way. Fix them one at a time.
Right', Down', Right, Down
The cube will look scrambled during this step. That's normal. Keep going.