My baking sheets keep getting rust looking stains and stains from foods like veggies. What can I do to prevent this and clean it. I use baking soda and plastic scrubbers but it does not work.
You could line them with parchment, silpats or foil when you use them- they're likely still to discolor over time, but much less. Sounds drastic, but have you tried oven cleaner on them? My go to for cooked on food is boiling with a strong baking soda solution, but pretty hard to arrange with a baking sheet.
People may be led astray by the fantasy world practices of TV chefs, who casually throw stuff on their always gleaming sheet pans, pour oil over it and bake it- in the real world, you do this and the oil will polymerize-just as on a cast iron pan- and be the Devil to remove.
Are you using nonstick coated pans and the nonstick coating is coming off? Sometimes that results in a rust spot where the metal becomes exposed. Maybe you can try under-cleaning it, like you would a cast iron pan. My favorite baking sheet Ive had for 15 yrs and has developed a black patina from all the baked in oils. I for one would have a heart attack if someone put a degreaser on it!:)
It's hard to beat a stainless steel scrubber as a decent cleaning tool.
I like to use Bar Keeper's Friend to scrub my baking sheets (actually, I use it on all my stainless steel cookware). Works well though it still requires a bit of elbow grease, especially with baked on stains and you probably won't get it pristine and stain-free as the day you bought, but it comes pretty close.