Fidelity through independence rehab prudential through life care
I would talk to your HR department, but here are the basics.
If you are still employed at one of the 401(k) sponsors, you may not be able to roll over that account.
If you want to increase your contribution, you can probably do that through your HR department or finance/payroll.
If you are active in a 401(k) or other plan now through another employer, you can have these old ones combined into your current plan. If you don't think your current plan (if any) is very good, look elsewhere.
If not, decide where you want to have your retirement assets located - Fidelity and Vanguard are both good choices. Either of these companies can walk you through the process. Make sure you have current statements from each of your old plans, call the contact phone number on the statements to get Transfer/Direct Rollover Forms from each.
You may want to consider rolling over you 401k's to a rollover IRA account. This will consolidate the accounts into one account, potentially reduce your costs and give you a wider variety of investment vehicles.
Walk into a Fidelity office with your paperwork and ask them to help you roll over the accounts into a new Fidelity IRA. They can also help you invest the money; perhaps their low cost ETFs would be appropriate.
How comfortable are you managing your old 401k money? If you enjoy managing your money and have the time to invest Scottrade or Ameritrade would be great options; low cost, great investment choices, and research is good. If you do not like to manage your money I would interview 3 financial advisor, you can find local ones on this site or Google advisors in your area. Hire the advisor or firm that fits the needs you have and that you trust. Great job on saving money and good luck on your search.