There is no specific mention about the photograph size. So its ok if you upload a recent passport size photograph with a plain back ground with a size of 10KB TO 100KB. Your face and ears should be visible. Do not wear sunglasses. But if you use spectacles regularly, you can wear them.

Signature should be in Black ink. with a file size of 4KB to 30KB. You should put your full signature on white paper with black pen and scan it. Your signature should not be in capitals. It should be un running handwriting.