I am member at different Stack Exchange communities; especially Signal Processing and Stack Overflow, but one thing I find difficult is that if I want to add/attach more than one photo/image/snapshot with my question, I am not able to do so. Please guide me, how can I do this?
You add them one at a time, using the upload link, uploading, and repeating per image. There's no 'bulk' upload option.
I suspect at very low rep levels, the 8 link maximum is in play, but it's slightly unlikely you'd hit that maximum.