For some reason, the fmc puts my T/C pretty much minutes after take-off. Am i doing something wrong when i am programming my flight in? going form KHOU to KDAL via CREID4.CQY.DUMPY3. I also have to maunally fix the route as there is a discontinuity in it(i have no idea why). Is the T/C issue because i am putting in the wrong estimated temperature, as i am using 40C as in the tutorial.

40C? That's very high.

I'm guessing your discontinuity is right at the beginning of your route?

If so, the reason is that the CRIED4 departure is a hybrid departure, meaning you get vectors to that first fix, and then it's pilot nav from there (one of the many simisms is that you're going to have an unbroken magenta line from origin to destination on every flight). This vectored portion is hard coded into the nav database as a discontinuity because a controller will be vectoring you and there is no route for the FMC to fly. Always, always, always look at what you're flying if you intend to fly it. In your case, take a look at the CRIED4 departure near the bottom of this page: http://airnav.com/airport/KHOU

SID/STARs are not required, and I'd suggest not flying them until they're properly understood.

 

Additionally, you may want to review the tutorial. If I remember correctly, the tutorial explains the reasoning of why you're entering a particular temperature value into the TEMP field. Instead of blindly throwing the number in on subsequent flights (missing data is almost always better than bad data), take a look at the tutorial's explanation and use that reasoning for future flights. Tutorials aren't a set of instructions to be used on every flight; they're a framework to give you an idea of what you'll need to do on other flights.

 

In your case, you need to find the temperature at your initial cruise altitude. Weather tools like ActiveSky have an option to provide the wind at top of climb, but you can also find this on wind/temp charts. I use ISA DEV because it's easier for me (either will work): http://aviationweather.gov/adds/winds/

Use the drop downs to find the altitude (closest to your cruise), and then click the button for Temperature (TEMP) or Temperature Difference (ISA DEV).

 

If this is too much for you to process right now (which is understandable), just leave the boxes blank.

40C sounds like a value you'd put in the assumed temp field, not as an estimated temp at cruise.