I would suggest you purchase a meter. You can get a decent digital multimeter for under $20.00. You do not need fancy though it is nice if the leads are a couple feet long.
If it saves ordering one unnecessary part it has paid for itself and you end up owning a useful tool.
Most places will not let you return electrical parts so if you order it, you own it.
A couple things to watch when measuring ohms and continuity
1. Always remove power from the machine otherwise you could blow your meter.
2. Always disconnect at least one side of any device you are checking. This eliminates the possibility of measuring an alternate/parallel circuit path.
3. When checking for closed contacts and continuity use the lowest scale (Usually 200 ohms). Then try higher scales. This scale is 0 to 200 ohms so if the device you are measuring is 300 ohms this scale would show an open circuit which it is not, you are just measuring outside the scale's dynamic range.

There is a good STICKY at the start of this forum about it's use.

Here are your parts
Replacement parts for WHIRLPOOL LEB6400LW0 | AppliancePartsPros.com

Here is the wiring diagram
http://www.servicematters.com/docs/wiring/Wiring%20Sheet%20-%203406661.pdf

Note: the following is just wild guessing without checking anything with meter.

First try flipping the breaker off/on slowly a couple times. Sometimes you can loose half the line without actually tripping the breaker and the heating coil requires the full 240 volts.

Next would be the heater. Unplug the unit, remove the heater and check it visually. If broken you should be able to see the break.
May also of sagged and is touching the case (grounded element).
If this is the case you will probably have to also replace the thermal fuse on the heater assembly as a grounded element often runs at full power and blows this fuse.

Next would be the thermal fuse on the heating element assembly.

Then the hi-limit and or the operating thermostat.

Then the timer.

Additional Info
If the thermal fuse is blown, you still have to find out why it blew.
Grounded element?
Note that the fuse comes with a hi-limit thermostat both must be replaced as the hi-limit should have regulated the temperature so that the fuse would not blow. The exception to this is if you have a grounded element.
Check that the belt is OK.
Check the seals (drum etc) in the unit. The air is pulled over the heating coils, through the drum and pushed out the exhaust. So any large seal leak will pull in room air and the cycling thermostat on the blower will run the unit hot.
Check that the lint filter is not coated with fabric softener residue which greatly reduces air flow.
Check/clean your vent system.
Check/clean the blower wheel.

If all OK you may want to replace the cycling thermostat as it's contacts may not be opening (welded shut).