I would definitely (without hesitation) recommend to undertake such a venture, and enroll in the program provided by Oxford House (OxfordTEFL) in Prague.
First of all, the process of being enrolled is serious enough and you will have to do a lot of work before the course starts (online tests and tasks as well as recommended material for self-study) and the interview either in person or on Skype with the Director of Studies.
I insist on your serious attitude to the pre-course tasks as if you do them thoroughly beforehand, you will enjoy the intensive course much more as you will feel more confident then.
Secondly, prepare yourself physically and morally to fully devote your time to studying, yes, the course is called "intensive" and it IS intensive. So just be ready to work hard during a month (there are some nice breaks anyway as going to a pub, still you will have weekends to enjoy too).
Thirdly, enjoy the process of "becoming" a teacher and bear in mind, this job is rewarding! There are ups and downs about planning, delivering a class - NB: there are experienced tutors to help you! Do not think the tutors will guide every your step and tell you what to do!!! You will have to explore and try out a lot of things on your own (spread you wings!). Whenever you feel worried, share that with your peers and/or with your tutor. All the staff are approachable and you can solve any issue, get help, get some comfort from any member of OxfordTEFL team.
Finally, you will be fully equipped with the basics and even some experience before you start your career as a teacher. Never give up! Students will be awesome and not... topics will be difficult and not... you will be nervous or relaxed! Go on with living that experience through! A new road of teaching other people will be yours!
Being an experienced teacher of English, I decided to obtain the certificate and I do not regret it. I had the chance to analyze my own teaching styles and find something new for myself! After the course the coordinator helped a lot in sending my resume to language school and I was bombardered with different job offers. My life is different now as I work for three different language schools (you can earn more money this way) - I should say, the main thing is having versatile experience now as different schools have different programs and you will meet nice people!
My favourite memory is the day of Moderation! We all were so nervous like students at the exam at uni, we did our best and passed it - it was a sigh of relief as well as the feeling of satisfaction. When you achieve every small thing in this course, you are happy (be ambitious)!
So, good luck! Go to Prague, a great place to visit and do something useful for yourself – invest money in your development! Trinity CertTESOL is worth getting!