What is the most efficient way to get to Kerbin orbit

[Eurojo46]

Plz help me!

[Scarecrow88]

Have you tried looking for hints/tips/help/videos in the tutorial section?

[Reactordrone]

The basics are,

To orbit you need horizontal speed, going straight up doesn't do it.

Go up until you're out of the thickest parts of the atmosphere, about 10-12km then tip over slightly from vertical and head east (90° on the navball), the rotation of the planet adds to your orbital speed, decreasing the amount of fuel you need to burn.

As you get about 70km altitude keep tipping the ship over until the heading and prograde markers are on the horizon(in between the blue and brown part of the navball. Blue on the navball represents sky and brown represents the ground, the line between is the horizon.)

Increase speed until your periapsis is over 70km. (about 2200m/s)

Edited July 26, 2014 by Reactordrone
changes km/h to m/s

[Red Iron Crown]

At the very simplest, fly up really fast, then fly east really fast.

More specifically (and assuming you're playing stock without the FAR aerodynamic mod, and using a rocket rather than a space plane):

1. Max throttle, turn on SAS, launch. Press space to stage as necessary during the following steps.

2. Ascend pointing straight up until you hit about 7000m of altitude or so.

3. Turn your rocket a little bit east (90 degrees).

4. Gradually turn further and further east, keeping your navball pip just a little lower than the yellow prograde marker. (The "gravity turn")

5. Switch to map mode, zoom in and click your Ap marker so the data from it remains visible.

6. Open the navball and continue turning lower and lower in the east direction, until you are near horizontal at around 50,000km altitude (direction pip on the border between blue and brown).

7. When your Ap altitude reaches about 75,000m, press x to cut your engines.

8. Set a maneuver node at the Ap marker, then pull the prograde handle (the one with the triangle) until the projected trajectory has a Pe of 70,000m or more.

9. Point rocket at the blue node marker on the navball.

10. When time to node is equal to half the estimated burn time, run up your engines and run them until the yellow bar beside the navball runs down. (The "Circularization Burn")

11. Congrats, you're in orbit.

[TheTranceMan]

in terms of sheer efficiency, turbojets are have, by far, the highest isp. feathering the intakes through the highest parts of the atmosphere to gain horizontal velocity is the real trick...