Hello there ^_^
Sure, um... let's see *scratchs head*
Literally translated Ninjutsu means Ninja techniques, so the term covers basically all techniques a ninja is able to use. That includes the usage of weapons, barriers, medical ninjutsu, elemental ninjutsu, etc. but not genjutsu since the effects of ninjutsu are real (often physical) and not illusionary.
Most Ninjutsu require the usage of chakra and often hand seals to mold and manipulatethe chakra properly.
Shape Transformation
As the name tells allready, shape transformation/manipulation is used to control and change the shape of chakra. The most advanced form is the Rasengan.
Nature Transformation
It allows the shinobi to apply properties of elements to their chakra by molding and manipulating the chakra. The results of Nature Transformation are the basic five elements (fire, wind, earth, lightning and water). On a more advanced level (kekkei genkai) the shinobi is able to combine two of the elements to create a new one, like wood (earth+water) and lava (earth+fire), or even three elements (kekkei tota) to combine earth, wind and fire, creating dust.
Yeah, that's all I can think of right now...