If you have a great deal of records you need stored, but also know that you will want to (or will be legally allowed to) destroy these documents at a certain time, you should consider a facility that offers both options.
Based on different laws, your records may need to be stored for a year or two, or even six years. If the time comes when you are able to destroy these records, and you have them stored on-site, the duty to shred or otherwise destroy them falls on you.
But, if you have your documents stored at an offsite storage facility, you will have other options. Many facilities will notify you when your documents are available for destruction (based on the timeframe you provide when you first store them, or based on applicable laws), and with your permission the facility will securely destroy the documents.
And even if the company does not have an automatic notification policy in place, if the company offers shredding services, you can simply indicate when you would like certain materials destroyed, and the facility will take care of it for you.
It's a good idea to choose a facility that offers both storage and shred options, particularly if you have a lot of documents, since storing in one place only to move everything to another location once the time comes to destroy the records only creates one additional step that can be time-consuming, tedious, and potentially expensive.
If you only have a small amount of material you are storing, and would like to do the shredding yourself, you should do careful research on a site like All About Shredders, which will help you decide what type of shredder will work best for your purposes.
Remember that destroying sensitive information about your clients or consumers is not as simple as dropping some paper in a recycling bin. Various laws protect consumers against identity theft, and you must comply with these laws. If you are choosing to allow an offsite facility to handle the destruction for you, be sure to ask the appropriate questions, and make sure you are comfortable with the facility's atmosphere and policies before you sign any contracts.