next lens choice for beginner

Hmm .. I suspect everyone's suggesting the 50mm f2.0 Digital Zuiko, as that's most assuredly a macro.

I'll defer to people who know better, but the OM lenses aren't going to be (anywhere) as good. Cheaper, certainly.

Remember that there's quite a few 50mm OM lenses, so you need to be clear which one you're looking to acquire.  I gather most people, when talking about 50mm OM lenses for use on their digital E series, look to the f/1.8 (but that's a generalisation based on vague memories of the forum, and the predominance of that variant being flogged on ebay).

Consider these links:

50mm / f1.2:

http://www.mir.com.my/rb/photography/hardwares/classics/olympusom1n2/shared/zuiko/htmls/50mm1.htm

50mm / f1.4:

http://www.mir.com.my/rb/photography/hardwares/classics/olympusom1n2/shared/zuiko/htmls/50mm1.htm#f1.4

50mm / f1.8:

http://www.mir.com.my/rb/photography/hardwares/classics/olympusom1n2/shared/zuiko/htmls/50mm1a.htm

The only specifically MACRO lenses in this range that I can see are f2 and f3.5 varieties, described here:

http://www.mir.com.my/rb/photography/hardwares/classics/olympusom1n2/shared/zuiko/htmls/50mm2a.htm