The first market I'm going to visit is Yihua.  This is a good one to start with because it is only 800m walk from the subway, no taxis/buses/bicycles to navigate.  There is also a KFC attached if you like such things.

Yihua has 3 floors, the first two are interesting, the top floor is PCs, printers and motherboards - these are the same the world across but probably worth a quick walk through.

The walk from the station is fine but like anywhere in the world, walking along an 8 lane expressway isn't that pleasant (noisy and polluted). Consider a mobike to make the journey short and painless.  There is plenty of sidewalk to bike/walk on and I found there were plenty of bikes at both the station and market but ymmv.