I need to resize images to given width/length, but when I do this in photoshop my images come out warped looking. What should I do?
Simple answer is you don't.
You can not change the width and height of an image by transformation without warping the image unless you transform proportionally. If you need images which are not proportional to the original, the best solution is to crop the images.
If you wish to change the size of an image in a non-proportional manner without warping it, you must crop the image, not transform it.
There are a few ways to transform without having warping occur:
For total size:
When I do a JQuery gallery that requires the images be of the same size - generally for me this is only my thumbnails - I first do a proportionate scale making the smaller of the two dimensions to be whatever value I want it to be, then I crop the other dimension, then save for web.
So if let's say my full size image is 1350 x 780 and I want to do 120x120 thumbnails. I would go:
I don't generally Crop my full size images but that depends on what type of jQuery code you've written. Just transform proportionately and it won't be warped.
I would advise either rescaling it proportionally or saving it at a fixed kilobite size while retaining the present quality to a fixed maximum file size. I like the scaling option myself for technical things. I like the fixed file size for things like facebook. It depends on your software in mine the utility is called scale and keep the keep proportional box checked.