It is not an unusual request for my clients to want to integrate Quickbooks and FileMaker and there are different methods of doing this. There are a number of different versions of Quickbooks application, but most of my clients use the USA version. We found ourselves often recreating the Quickbooks schema and if you are starting afresh, it is convenient to use the same table and field names in FileMaker that are used by Quickbooks when integrating.
We have a personal favorite web site that keeps track of the latest Quickbooks schema at www.qodbc.com by FLEXquarters North America Sales. Since we found ourselves going back to this web site to check the latest schema, we decided to create a FileMaker solution with all of the Quickbooks schema. But in addition to having all of the Quickbooks schema, we wanted to address the fact that this occasionally changes. So we wrote a script that goes to this web page and web scrapes the schema and then recreates it in a FileMaker solution all automatically. It does require the use of the Monkey Bread Software (Monkeybread Software - MBS FileMaker Plugin 5.4) plugin to work. However, if all you need is the schema as of Oct 2015, then you can still make use of the database.
Here is the database and it is being freely distributed to the FileMaker Community. If you make use of it, appropriate credit in your solution would be appreciated. http://www.TaylorMadeServices.com/FileMaker/QuickbooksSchema.fmp12.uu You will need to uudecode it. The database automatically logs in as Admin with no password and full access.
You can also use this database example if you want to see what it is like to web scrape data from a web page and then use it to alter or create schema in FileMaker.
PS: Note that this is not the schema for Quickbooks Online. But if you are interested in Quickbooks online, check out fmQBO by Geist Interactive. I really like it as a great API to integrate Quickbooks Online and FileMaker.