One annoyance about SQL Reports is that every 12 hours (720 minutes) the reporting services libraries remove themselves from memory — they "Recycle" themselves.
The result is that on any given day, when a user goes to the http://localhost/reports web site, they’re stuck waiting for SSRS to load from scratch — which can take up to 2 minutes.
To make this less annoying you can change the "RecycleTime"
Navigate to the SQL-Appropriate version of this folder:
C:\Program Files\Microsoft SQL Server\MSRS10_50.MSSQLSERVER\Reporting Services\ReportServer
Open this file:
Search for RecycleTime:
Replace the 720 value with something larger like 2880.
2880 will keep the services running for 2 days, so the slow start will only be every couple of days, not every 12 hours.
You could also use other values for longer or shorter "stay in memory” times.