Whether you litigate, mediate, negotiate or collaborate, there are 5 key areas to address:
1. divide property
2. assign debts
3. determine spousal support
4. determine custody and visitation
5. calculate child support
Make a list of all your property. Real estate, time shares, cars, boats, motorcycles, bank accounts, investments, retirement (pensions, IRA's, 401k's), artwork, business interests, etc. If it has value, put it on the list. However, stop before you get to clothes, salt/pepper shakers, etc. There is a point of diminishing returns.
You can do a 50/50 split by agreement. Litigation may be required if one side or the other won't agree (and in some instances there are good reasons not to) to 50/50. If you want a 60/40 split and have to litigate, the question is whether 10% of your marital estate and risk of not getting the favorable outcome are worth more than the $20k, $50k or ?? that your trial will cost. Right now with real estate and investments down, litigation is frequently a losing proposition.
Debts are fairly straight forward. Whoever gets the car also gets the loan. Whoever gets the house, gets the mortgage. Credit cards can be hard because there is not a particular asset associated with the debt, as with a car loan. If the charges came from clothes, food, etc. for the family, then it can/should be shared.
Spousal support is usually based on the recipient's need and the payor's ability to pay. "Need" and "ability to pay" are based upon income and expenses. Work up a budget. Be realistic. Whatever you cut now, may be gone for good.
Custody and visitation will have to address legal custody, physical custody, and visitation. Legal custody (the power to make medical, educational, etc. choices) is usually shared on paper but decided by the physical custodian in practice. Physical custody is simply with which parent do(es) the child(ren) live with more than the other. Visitation is the non-physical custodian's time with the child(ren). Visitation can be anything from nothing to equal time. Wednesday night for dinner, alternating weekends, split holidays and two weeks in the summer is fairly common.
That being said, there are few things worse than being locked up in a house with a teenager who does not want to be there. Teenagers sort of "dictate" their visitation. Either school/extracurricular activities limit options or their attitudes to one parent or the other do.
Child support is usually a straight statutory formula. Mom's income, dad's income, an adjustment for spousal support if any, work-related daycare, and cost of health insurance go into a formula and whatever pops out is the amount. Do a google to find your state's child support enforcement office. They frequently have on-line calculators you can use to get an idea of what child support will run
That is a very rough overview. The devil is always in the details. But, getting a balance sheet of assets and liabilities, and an income/expense statement will move you along considerably.