Well, there are many big data initiatives and there is a lot of interest in the market. So, yes big data is an interesting career path.
What is big data? Many things, but in general the "art" of collecting, correlating and understanding data - in massive volumes and at rapid ingest speeds - to drive businesses to better support their customers, their goals etc.
How to get started? Look around the forums, but also on Linked-In where you see job postings. Two avenues to consider for learning:
- Analytics, look at this Oracle link: http://www.oracle.com/technetwork/database/options/advanced-analytics/index.html
- Hadoop and NoSQL database, look at the big data appliance page, and possibly take a class on Hadoop