You will need Nvidia dds plugin . . it comes with .dds file opener to edit in PS and has Normal Map filter which can generate normal maps,for specular map is just to create a copy of your colored texture and then desaturate the color to zero its just black and white , making it brighter is more shine effect and making it darker is less shine effect as specular. .
basically you can create normalmaps in photoshop at your own custom design . . just google and download that plugin on nvidia website..
thers 2 version.. 64 bit installer is for 64 bit photoshop and 32 bit installer for 32 bit photoshop ..
the last thing is find tutorials on youtube on how to create them . .