Dungeon 5

 Dungeon 5... If you go up, you'll find this locked door, so nowhere to go now but right.
After passing some Blue Bubbles, here you'll meet Gibdos. Basically, they're Stalfos but tougher. You can bomb this wall here, but I recommend going right, so beat the Gibdos and push the block.
A Key. You'll also meet a Red Bubble. Touch it, and you won't be able to use your sword again until you find a Fairy Pond, drink some Water of Life or touch a Blue Bubble. All three are plentiful in this game, and Red Bubbles are rare, so don't despair.
Go down from the previous room to find the Map. Now bomb the wall on the left.
A Fairy Pond in a dungeon?! How... forgiving of the game. Head left when you're done healing up.
The Old Man... bomb the wall on the left and you'll be taken back to the first room in the dungeon.
Go up and through the locked door. You'll meet your first Wizzrobes here. Red Wizzrobes disappear and reappear, shooting beams of energy at you. They're nothing too tough.
When you see this Key, don't fret that you can't reach it yet. We'll fix that soon enough.
This is why I told you to bring some Meat. Until you feed this Merchant, you won't be able to get by.
In this room, push the block up, grab the compass, and go to the room on the left after bombing the wall. Immediately return, push the block again and go up.
Clear this room, push the block and take the stairs.
When you come out, bomb the wall on the left for a SECRET ROOM. How secretive!
Hopefully you haev 50 Rupees. If not, you should fight some Zols until you do. More Bombs never hurt nobody... 'cept maybe The Cheat.
Go back to the right, then down. Dodongos! You should be fine if you have at least 6 Bombs.
Go down again and take the stairs to find the Ladder.
Return to the Key you couldn't reach before. With the Ladder in your inventory, reaching it will be no problem.
Go back to the block-pushing room and go to the left. Go up here if you want a "hint" from the old man. Otherwise, go down.
These are the bluer, tougher Wizzrobes. They don't teleport, but they zoom around the room and are a big headache.
Keep going down until you reach this room. Defeat the enemies and push the block to reveal a staircase.
At this room, you need to push this block, but you need to push it toward the center of the room, otherwise you'll block the exit.
The boss is the lowly Patra. You might remember it as a sub-boss in Dungeon 9 of the original Legend of Zelda. I guess in this game he got promoted, probably do to the absence of Gleeok. Just stand to the left of it and slash away the mini-Patras, then go for the main part. Since it only moves up and down, you shouldn't even get hit.
Once again, Triforce-victory is yours.