Hello, I'm a 30 year old man from Holland and I want to immigrate to the USA to go live together with a woman that is a US citizen. I know I could try and get a Visa through marriage but I am not sure if that will allow me to also work over there. I know that she will not be able to support me and I would not even want that either. So I want to try to get a visa through work. I had a look at the website I think I would have to get an employment-based permanent visa, and 3 preference would be my category. I am an experienced IT support engineer. I have 8 years experience at doing work as a network administrator and also helpdesk work. And I speak 3 languages which are dutch, english and german. I have been looking through some USA job sites and see that most jobs require already being a US citizen are be allowed to work there. But I need to have a job offer to apply for this kind of visa.
Can you give me some advice on how to get started on this?

At a minimum, it will take at least 3 to 4 years to get an employment-based permanent visa (green card). Rather than pursuing an permanent visa right away, it probably would make more sense to first obtain a temporary visa (such as an H-1B or a J-1 visa) and then once in the US seek sponsorship for permanent residency (green card).

You need a job offer to apply for an H-1B visa. On the other hand, you do not necessarily need one for a J-1 visa. To get a J-1 visa, you need to go through an accredited organization, such as Council Exchanges (CIEE) or the Association for International Practical Training (AIPT). Those organizations, for an additional fee, can assist in finding you a placement with a US company.

Of course, if you decide to pursue a visa through your US girlfriend (such as a K-1 fiancé visa), you would be entitled to apply for a work permit as soon as you arrive in the US.