Make sure you have the funds.
Before getting up a lawyer, I would imagine you have a "non-official" agreement with the other parent. make it official, try to get a signature, notarize it if possible. That way there is no confusion and he said/she said stuff.
Do your research for a good and affordable lawyer. Custody issues are not that complicated, but they do know the lingo, what and when to serve, and the other parent has to deal directly with them (if they don't have a lawyer) so the harassment is cut in half...
I had to change lawyers in the middle of the process, because my firmer lawyer was more concern with her friendship with the opposing lawyer than with the case, and she moved too slow for comfort - so, look for clues; if you feel uncomfortable with a particular lawyer, state your needs, they do want to keep you around.
My new lawyer was much more aggressive and he did make a point to spot the threats from the opposing party.
Document EVERYTHING. Try to have a type of communication that would leave a record, voice messages, text messages, letters, e-mails, etc.
Write whatever the other party did. They didn't want to return the child, they were more than 15 minutes late to pick up or drop off, insults, anything and everything.
Keep a calendar and mark the days the child is retrieved, times, etc. Put a date on the documentation, write facts, include times, dates, what happened - period.
If you are the serving party, be ready - you have bruised some body's ego, and they are coming for vengeance. Insults will come, promises will come, friends with "good intentions" will overflow. Listen to people you trust and that know what you are going through as a parent, as a mother, as a single mother.
KEEP ON GOING:
After filing comes mediation, make sure you attend. Be calm, out emotions aside and present facts. Give the court any documentation you have at least 20 days before mediation day, that way the mediator has a chance to review it. Speak ONLY about what is pertinent to the child, you are not there to confront the other parent, but for the well being of your kid. the other parent will try to get a rise out of you, and what better place than in front of the person who has the most say in this process.
The Mediator is the "battle to win" because the judge generally approves the mediator's recommendations - 95% of the time.
Write whatever the mediator says, there has been times in which the mediators tells the parents one thing and end up recommending another - and you can appeal that.
Court doesn't come right away, the court wants to give LOTS of chances for the parents to communicate (it took me two years from the first filing to come and see the judge) if they don't see them communicate, then they take the ruling and final order.
Needless to say, if you can come to an agreement that would be fantastic, aim for that. Put it in writing, both of you sign it and submit it to court.
My son's dad an I want a slightly different plan form the one approved by the court, because my son will be starting pre-school soon, we live further apart and it is best for the child. We will try it a month (written agreement) and if it is beneficial for the child, we will adopt it - written and with the judge's signature - a must! you never know when someone turns "forgetful" or something...
One more thing, I know many, many are against taking matters to court. I am a Christian, and thought long and hard before coming to this decision. I tried taking these matters before the church - that particular church didn't help, and the situation was getting worse by the minute.
Court helped it getting solved.
AGAIN, if you can solve it before court - then go for it please!! - if you find yourself trapped and fearful - protect your child, protect yourself - a hurt ego can be very dangerous.
Seek counsel, do your research - and don't commit to a plan you don't think is best for your kid or kids.
The dad and I are able to move forward now, we have a base - we are not in love with it, but it serves its purpose, and we take it from there.