Arrows keys or WASD to move. Use X or K to do an action, press J or Z to swing your sword, and press C or L to use whichever item you have selected. Press H or V to cycle through items. Use Space for Select/Start.
This is where I've posted the beginning of my work on this project, including basic logic and the first couple items. zeldacraig and I are working together to try and build a massive Zelda adventure in Scratch.