You can make subscription for maintenance offered by your web designer or ask him to provide training to your company maintenance specialists.
If you choose to have a company specialist, your website must be appropriately designed with a control management system (CMS) for easy content control. Thereby, a person with average computer skills could be able to manage with the content update.
The update is extremely important for your website. If you do not do that, you will quickly lose the users interest. Currently the number of dead sites is bigger than the number of existing ones.
The worst advertising is a website presenting outdated information. Leaving your website without regular maintenance means wasting the money paid for web design. Thus, your website will not help your business. In fact it will prevent! If your website contains outdated information and your partners know they cannot believe it, why do you think they will believe your e-mails, letters or faxes?