Once you're still available for, and looking for work you can continue to claim your JB, both before and after the baby's born. If you continue to claim JB, you can claim an increase for the baby (€29.80 pw).
When the baby is born, you may be eligible for One Parent Family Payment.
You may be able to claim both (JB would be paid at half of the rate you get now in addition to One Parent Family Payment).
If you're not available for work, and you have no income while waiting on One Parent Family Payment, you can apply for Supplementary Welfare Allowance, which is dealt with by Community Welfare Officers based at local health centres. They may also help you with an application for a medical card (if you don't already have one).
You'll get an application form for Child Benefit in the post when the baby is registered - it has no effect on JB so there's no need to deprive yourself of the payment.