Verified answer

Le matin and la matinée both mean the morning but there are some subtle differences... I'm not good at explaining it so look at this for more info.

http://french.about.com/library/weekly/aa070100.ht...

Du matin is used when you're talking about time, i.e. Il est huit heures du matin (8 in the morning).

I'm not sure if "Dans le matin" is correct, as you could simply say "le matin" and it could mean "in the morning," for example, Le matin je vais à mes cours = In the morning I go to my classes.

I'm not sure if this is 100% right, so don't quote me on this.

dans le matin=in the morning

du matin= morning

la matinée= the morning

le matin and la matinée are just a gender difference.

Je mange des fraises dans le matin = I eat strawberries in the morning

J'aime la matinée (le matin)