Find Slow running queries using the Reports in SSMS
1) High CPU consuming Queries: To run the report right click the server name in SSMS>reports>standard Reports>performance –Top queries by average Time

Figure 1: How to get to the performance reports

Figure 2: Top 10 queries by CPU time
2) Queries with highest IO: To run the report right click the server name in SSMS>reports>standard Reports>performance –Top queries by average IO
Figure 3: Top 10 quries by IO
3) Server Dashboard: To run the report right click the server name in SSMS>reports>standard Reports>Server Dashboard

Figure 4: Server Dashboard