Help needed for new Prusa i3 user

Hi to all, im new to 3d printing so i need some help for a couple problems i get. I completed my prusa recently, the problems i got are :
1. When i send my extruder to x home, he activates endstop and keep moving and vibrating for couple more seconds, all other axis works fine and stop when hits endstops.
2-3. I started test print (20x20mm cube), printer starts to print and it looks like nozzle dont get up, so nozzle keep going through already printed filament... I cancel print and all i get is some kind of scaled cube not even close 20x20, and in slic3r cube is not scaled down.
4. When i calibrate my extruder i make line at 150mm, and hit in pronterface to extrude 100mm, and he gave me only 38 mm. Earlier e steps was 600, so now it should be 1579, i think this is too high but i try and i seems good, is this ok ?

Pls. help me if you can im desperate, and i dont know what im going to do. I dont have any successfully prints so far and i'm totally noob.
P.S. Sorry for my bad English

Hi,

Your first problem sounds like the classic x end stop not set up correctly as the normal configuration is the x end stop is at x max and the firmware is set up incorrectly and/or the endstop is not plugged into the x max header on the electronics.

Sounds like you should also look at calibrating your z axis. There is plenty of information in the wiki.

You need to get everything moving correctly before trying to print, otherwise you may damage your machine.

The extruder steps sound fine to me.

Thanks a lot m8, i do like you told me and finally got my first print In the middle of printing extruder motor stop working for a few moments and he was really hot so i cancel my print, what could that be ?

Current from your step stick driver is too high, I used Tom Sandlanderer's guide to adjust my motor current, but I keep the motor warm by around 30'c I think.

Here is some info you should look into

incorrect dimension - check your steps/mm setting, use prusa calculator (google it) as a base then work your way up to get finer dimensions (80 steps/mm throws me offset by about 1-3% the actual dimension)
motor being too hot and shuts down - too much current supplied to the motor
on certain layer the print somewhat shifted by x/y axis - current on step stick too low

Thanks for the answer it helps me a lot, i increase current on step stick and now it seems to be ok, motor is heating but not too bad and he is not stopping. Thanks again