and honestly.. if your knowledge of photography is so limited that you can't even know what basic specs would suit you, avoid sim lim at all costs!!!
and try reading a nice newbies book at the library.
I am interested in buying a second hand DSLR but i don;t know what to look out for when purchasing it.
May i know what are the relevant specification i supposed to look at when purchasing a secondhand DSLR.
Have a look at the entry level models of all the camera manufacturers. Next: read up about these models. Clarify questions about features and specs. Your library has plenty of books to fill a weekend of reading and understanding. As mentioned in another thread: check the Classifieds here for 2nd hand pricing. It might be better for you to get a 2nd hand system from a photographer rather than from a shop. Without much knowledge you are just prey to the sales men.