Please have actual project experience before going for Certs.
Many blogs are there, eg :- http://scn.sap.com/community/training-and-education/certification/blog/2012/12/06/how-to-prepare-for...
After Completion of ILT or OLT SAP Training you have only 1 moth Time Period for Appearing for Certification Exam. So better you first certify and then search for better opportunity. Otherwise Better option is First go for live Project Experience and Clear your all concept and then go for Certification .
It is always worth the give the certification after the end ofthe academy. Thats what I did.
If you give too much of time after academy, then you would loose that tempo and there is every chance you tend to forget many fundamentals, which are key in passing the exam.
Please go for exam after academy course.
If its an Associate Certificate you have applied go for it and its for beginners and you have applied for professional certification better to have project experience and then go for it.
for more details visit :-https://training.sap.com/
what ever is the way ..good luck and all the best...