1. Navigate to Central Administrator > Application management > Manage Web Application
2. Select a web application and click on 'General Settings' and select 'General Settings' (as shown below)
3. Some of the basic things you should be aware of the web application configuration are the following :
a. Default Quota template - You can create the web application based on a Quota template which you can create and manage it. The quota template helps you manage the storage limitation for a site and can send warning emails on reaching certain limit.
b. Alerts - You can turn on and off the Alert configuration for the entire web application
c. Send user Name and Password - It's self explanatory. If you want the system to send users their usernam and password, set it to "yes".
d. Recycle Bin - Configure your primary and secondary stage of the recycle bin here. You can set the days afer which the system can Expunge items from your recycle bin.
e. Maximum Upload Size - You can limit your maximum single upload size. This includes uploading a document on a document library on this web application.