new stuff  

I have a nikon d60 and as a amateur I would suggest buying following accessories if you do not have it.
- lens atleast 200mm
- tripod
- UV filter
- remote (if you are into night photography)
- camera pouch

If you are no amateur then I do not think you will need any other filters. Atleast thats my opinion from doing research on the internet.

Sony makes a wide range of quality accessories for its Alpha DSLRs. What you need depends on the kind of photography you are interested in. Some things are aseful to most photographers: a UV filter a skylight is an acceptable alternative) should be permanently attached to every lens ou own. A polarising filter is very useful for controlling unwanted reflections and glare, and for adding richness to skies and colour saturation to foliage.

A solid tripod (and/or a monopod) with a good head is a great buy, and an external flash gun (sometimes referred to as a strobe) will amaze you with what it allows you to achieve.