I agree with the idea of going slowly. Perhaps in a month or so, when the ads and censoring kick in, people will be certain they don't like that, and willing to chip in to have it removed.
It would have to be decided what a donation "means," and who would know about who donated. I don't like the idea that if someone gives money, or gives more money, this is widely known or even known to the mods/admins. This could lead to the perception that some people get special treatment or different moderation standards because they gave a lot of money.
In my opinion the donation should be such that the mods (and other users) have no idea who donated and how much per individual, and it should change nothing about the person's status or rights within the forum. Is it a donation to support the forum, given voluntarily with no other strings, or a payment to buy services/extra services? This needs to be made clear.
Also, donation must be through a secure method and relatively convenient. I don't have a Paypal account, for example. I'm not familiar with the various other options. If something is set up, I will take a look at it and try to figure it out.