This question almost entirely depends on what Tools you have in your Administration Center. Tools available for clients are listed here in this article: https://help.beyondindigo.com/hc/en-us/articles/202003783-Beyond-Indigo-Tools-available-to-Clients-for-Free
Your Project Manager will also review which Tools would be preferable for your type of site/business model.
Once you have your site launched and your Tools set up in the Administration Center, then it's very easy for you to manage many of the changes on your website yourself. Some of the most popular changes are with Staff listings - you will be able to add new staff, their pictures and biographies yourself. Another popular and useful Tool is the Specials Tool. Have a coupon or special offer running? You can add this information yourself, and also add a picture of PDF file for your clients to download and bring in with them. News and Events are also excellent Tools, and it's important to keep this information up to date. Posting every once in a while to your News section is worse than not having a News section at all. So be thoughtful about what Tools you choose to manage on your own.
All other items on your website - the majority of the content - can be changed, updated, removed, or added - via a Help Desk request. Simply open a new ticket with the changes you need to the specific page or section on your site. You can also submit new photos for the Help Desk to swap out anywhere on your website - just attach the photo to the ticket.
If the Tools overwhelm you, do not worry! The Help Desk regularly updates News, Events, Employment, Specials, and Staff using the existing Tools for clients. Don't feel that if you have the Tools that YOU have to use them - you can always ask the Help Desk to make the updates for you too!