Well there are many many ways you can enter the quantitative data (generated from surveys) into a computer. Most of the people I know use either use a simple Excel table or very very complex MS Access data entry file. However both of these programs are not created for data entry purposes and hence are not so handy for that purpose.
There are several software out there in the market which you can buy to do the job, or you can outsource the data for entry or create a program for the very purpose yourself. All of these options require extra resources. SPSS, the most popular data analysis program also has a data entry module which is great but that is not free.
The best option would be to have a data entry program which is made just for that purpose, is easy to learn and use and most importantly is free. Thankfully there are 2 such software:
"The Census and Survey Processing System (CSPro) is a public domain software package used by hundreds of organizations and tens of thousands of individuals for entering, editing, tabulating, and disseminating census and survey data."
"EpiData Entry is used for simple or programmed data entry and data documentation. Entry handles simple forms or related systems Optimised documentation."
In my view using using Excel and Access have their strength but for any survey with more than a page long questionnaire and more than 40-50 respondents, it is better to use one or the other of the above.
Range checks, value lengths, logical jumps, automatically calculated fields, data validation on double entry, find duplicates, assign values for missing or not applicable values etc. are some the things that needs to be done to maintain the integrity of data. Both of the above software can do that.
The files that are created in these programs can easily be exported to major analytical packages like SPSS and STATA.