Okay... first off, morphs can be dominant, codominant, and recessive. Depending on the morph you use depends on really what you get.
A normal has no special mutation that can guarantee a change like a morph does. A pastel and a normal would get you pastels and normals. Normals CAN have genetic influences, however. A pastel and a light normal MIGHT make lighter pastels and normals than a pastel and a dark normal. Might.. Sometimes the snakes that are just normal don't pass on these traits. Sometimes they do!
Some people breed dark normals to albinos and breed the dark het albinos back to albinos to create darker yellow albino snakes.
You won't get a different morph using a normal, but it could help with some things, if you know what you are doing.
A codominant animal (pastel, spider, lesser, etc.) to a normal makes normals and that morph..%50 chance per egg.
A recessive animal to a normal creates all het for that recessive trait. Meaning they look normal, but when bred back to the parent will create babies with the recessive trait(Like albino, pied, etc.)
Dominant animals to normals will also create themselves and normals. The difference with them is they do NOT have a super form unlike codominants(if you breed pastel to pastel you can get super pastels. If you breed the regular dominant pinstripe to pinstripe, you just get pinstripes)