When reporting a t-test you should include the following information. 

  1. State whether you used an independent or paired t-test: You should use a paired t-test if you took repeated measurements of the same variable from the same sample. Otherwise use an independent t-test.
  2. Check and state that your data is normally distributed: Your data should follow a normal distribution. Check this by plotting the data on a histogram or scatter graph. For an independent t-test you should plot the data for each group. For a paired t-test you should plot the paired differences. If the chart peaks in the middle and is roughly symmetrical then your data is normal. Otherwise, you should use a Wilcoxon or Mann-Whitney test. 
  3. Check and state that variances are equal (for independent t-tests): you can use Levene's test for this. If variances aren't equal, you can correct for this by adjusting the degrees of freedom using the Welch-Satterthwaite method and by not using the pooled estimate for the error term for the t-statistic. Some statistical softwares will do this for you automatically - look for a row in the output called something like "Equal variances not assumed". Alternatively, you could use a MannWhitney test. 
  4. State the degrees of freedom and the test statistic: Write this as t(df) = t-statistic.
  5. Include a measure of precision: generally a 95% confidence interval

If you want to plot your results you should use a box plot (for exploratory research) or a confidence interval plot (if you are testing a hypothesis). 

See the SAMPL guidelines for more general information about how to report statistics, and this guide to learn more about common statistical tests.