Inputs on certain queries with regard to obtaining LORS will be extremely helpful. Is it important to obtain letters of recomendation from professors only. Will obtaining a LOR from a lecturer carry equal weightage?

In case of practising attorneys, is it essential to obtain an LOR from the partner of my firm? Can I obtain it from any other professional whose seen my work.

Generally, professors are preferable to lecturers. However, what's more important in my view is for the recommender to be able to show a strong rapport with the recommendee and make the letter sound personal. So a lecturer who knows you personally and has had the opportunity to observe your work closely might be a better choice as he or she would write a more personal letter than a tenured professor with whom you only took one course and who most likely can't even tie your name to your face. Same goes at work where it would be better to get a letter from the supervisor directly above you who is responsible for assessing your work as opposed to a parnter in the firm who barely knows you.

Moral of the story, then, or the rule of thumb if you like: the more personal the letter, the better...