For a slideshow : **[slideshow=id,width,height]**

For a album : **[album=id,extend]** or **[album=id,compact]**

For a gallery : ****

For a single picture : **[singlepic=id,width,height,mode,float]**

For a image browser : **[imagebrowser=id]**

To show image sorted by tags : **[tags=name,name,name]**

To show tag albums : **[albumtags=name,name,name]**

Developer website: http://alexrabe.boelinger.com/wordpress-plugins/nextgen-gallery/faq/