what is the easiest way to move Nokia (symbian e series) content, such as contacts, inbox, photos etc to an android phone? I can extract a backup from nokia but it's in .nbu format
By far the easiest way to transfer anything contacts related to an Android phone is via GMail.
When I moved from an old Nokia phone to my Android HTC Magic about a year ago, I downloaded and installed the Nokia Suite of tools for my phone from the Nokia website, installed them, copied my contacts into the Nokia Suite app on the PC, then did an export from the Nokia Suite contacts app to a CSV file. I remember seeing the Noklia-only NBU format as an optin, but if you're in the Contacts-only part of the suite it should also allow the CSV export (as this is also the easiest way to do a one-off import to other apps like Outlook).
At that point you can go into GMail, click the Contacts link, then at the top you should see an "Import" option, use that to upload your CSV file. All that you should lose from this is the contact's photos, but you can easily back up your contact's photos from the Nokia suite, and then just upload them to GMail one by one, or alternatively let Android on the phone sync with Facebook, etc and pull the Contacts photos from there itself.
You might find that if you already had some people in your GMail address book that you'll have a few duplicates now, just tick the relevant Contacts in Gmail and select "Merge these contacts".
For content, such as photos or music, which are probably just files on the Nokia's SD memory card, the easiest way is to attach the phone to a PC, select Data Storage/Transfer Mode on the phone, then open the SD card drive on the PC, drag all the relevant files onto the PC, then attach Android phone, mount SD card and drag all the content into the relevant folders on the Android's SD card.
As for messages, do you mean SMS/MMS text messages? As far as I know there aren't easy ways to transfer those between phone OS's at all (unless you're already doing something like sync'ing them to GMail).
I have to agree with GAThrawn, that using GMail to transfer your contacts and calender items is probably the best way. But there is an IMHO easier solution to get your data from the Nokia phone to GMail: Nokia's Mail for Exchange together with Google Sync. Google provides a couple of help topics to get you going.