Where and How do I put i NPC's?

Beaten because I had to upload a picture, bah.

1)NPC's. I have no idea how to place them, needless to say where they are. Where are they?

1) NPCs are just Events that can move around. Observe (RM2k3, since RMXP still refuses to work):

2)How do is set where they go?

2) Either using randomized movement, or by building a "custom pattern" (check the "Movement Type" dropdown box). You can also move Events by using other events, using the event command <>"Move Event"

3)How do I incorporate a story? I mean, what do I have to do to make text, etc...To make a good game.

3) Event command <>"Message" will put text on the screen. Using multiple <>Message commands, you can have the effect of conversation. How to make a good game, though, is an unanswerable question - just make a game that you won't mind playing over and over to fix random errors.

4)I downloaded some sprites, and when I try to import them, it says invalid image size. Why?

4) Because.. the image.. is an invalid size? What's the image type / RPGMaker version, and the size of the image in pixels? And are you clicking on the proper folder to import first? (On the left side of the Resource Manager, there's a bunch of folders. Click on the file type you want to import, THEN attempt to import it.)