Recommnd me a certificate to study for
CCIE.
1examamonth.com would be a decent place to start.
For more focus on Route and Switch is common. If you like Voice/Collaboration, data center, wireless, etc there are specialty programs.
CCNA Route / Switch should be the first test and doable in about 3 months.
Then I'd go CCNP which can be done in another 6 months.
CCIE can be done for most in 18-24 months. Keep in mind for this about 3-6 months prior to the test you will be wanting to put about 40 hours a week of lab time in.
At the CCIE level you pretty much are always going to have a job and looking at around $150k as a minimum pretty much anywhere. Even as a CCNP, $100k is relatively easy to get with experience.
http://www.cisco.com/web/learning/training-index.html