Stata is a statistical package for analysis, graphics and data management written and published by Stata Corp.. It is in my opinion an extremly well written piece of software, but there are a number of other packages available such asS.A.S., S-Plus, R (the GNU 'free' implementation of S-Plus), or any of the other common Statistical pacakges.
Stata is an excellent piece of software for data management, statistical analysis and the production of graphics. Part of its power (as with the other statistical systems mentioned above) comes from a command line interface that is combined with its own scripting language (called Do (*.do) and Ado (*.ado) files). This allows a user to perform their manipulations and analyses in a replicable manner so that a set of published results may be recreated at any point in time in the future (providing you have access to a functional copy of Stata). Stata will, if instructed to do so, keep a record of the changes that occur to your data during manipulation, or the results of any analysis you may carry out (stored in a log file), and it is recommended that you make use of this function for recording the manipulations that are performed on your data.
You should never use Excel for statistical analysis, see the section listed below.
Getting Started with Stata - A brief introduction and links to resources for learning Stata.
Hints & Tips - Hints & Tips on Stata syntax and data storage.
Stata Do-files - An overview of writing Stata Do-files.
What do the error commands mean? - An explanation of some of the errors that you may encounter when using Stata.
User Written Programs for statistical genetics - a list of useful programs written by Stata users to deal with genetic data.
Useful programs - A list of useful programs that will facilitate your data management and use of Stata.
Why not use Excel - an exposition of why to avoid using Excel
Code repository - Useful Stata code which you can copy and paste into your own do-files.
Data Management Tutorial - A tutorial and sample scripts for combining output from automated genotyping machines