What are the sources for learning bioinformatics(books, websites/MOOCs)? Does it require prior knowledge of programming language because I am a complete noob when it comes to programming language.
Learning a language such as python or perl is almost necessary.
You might have a look at coursera.
There are quite some bioinformatics-oriented courses:
University of California San Diego has a series of bioinformatics courses, with one that seems made for beginners in programming:
I haven't had a detailed look at this one, but I liked their more advanced courses.
In coursera, the courses are often organized in so-called "specializations" which give you a certificate, but are not free. However, you can normally enroll to individual courses without paying.
I would also advise learning how to use a UNIX-like command-line environment, and tools such as sed, awk, grep.
The following sites might be good for this:
The scope of the latter is broader, and the things they teach could be valuable if you want to do scientific programming in general.
From what you say I would definitely not start by learning a programming or scripting language which may only be applicable to certain types of problems.
I would start by reading an introductory book on bioinformatics with a wide general scope. Then you can see what area or areas interest you and find out what tools (programming or otherwise) you need to become familiar with to solve problems in that area. (Because to really learn bioinformatics you have to solve problems.)
There are no doubt several suitable books. The one I am familiar with as it was used in my University is "Introduction to Bioinformatics" by Arthur Lesk (Oxford) 4th ed (2013). However it doesn't cover RNAseq, so unless there is a new edition in the pipeline you may be better with something more recent.