As ive worked in the security field for a short stint, there are many things ive picked up.
1. Learn short cuts in a job, and one being able to pick the little tools on the net.
2. Read a lot, it is very important to keep up to date
3. Script.

1. Short cuts.
To test a web server response, use hurl.it
https://www.hurl.it/
Its an amazing site to check responses from a web server.

To check SSL certs, use the qualys lab server test.
https://www.ssllabs.com/ssltest/
Great site to test your ssl certificate and potential vulnerabilities

To check the activity of website and how things run,
The firebug plugin on mozilla.
Amazing little tool. Of course will google you can use their developer stuff. Great  way to learn.

Subscribe to US-CERT. Important! Of course follow my blog too, im very connected to people and their blogs

2. Read heaps.

Pick up CSO Online. Great articles.
The RSA blog
Depending on your flavor of security, you can always check out vendor blogs
Threat intelligence wise, i found Lockheed Martin and some of the BAE articles are nice.
Dark reading
Again check my blog!

3. Script.

Learn PERL and Python. Code Academy has some good stuff, check them out too.
MIT online or Stanford too are nice places to learn.
Scripting, no not my blog, lol.

Hope the advice helps.