After 2 months, my site had not appeared in DMOZ, so I was advised to resubmit and maybe try a different category. I.... am not sure about continually resubmitting each month as advised, as I think this may be irritating for the editors.
Pretty lousy advice, generally speaking. I would hope that you picked the most appropriate category first time around therefore resubmitting to a different category in the hopes of getting reviewed more quickly could just end up adding more time to the time it will take to get your site reviewed since the editor in the "wrong" category will just end up sending the site over to the "right" one where it will start waiting all over again.
Resubmitting every month doesn't help your site get listed more quickly -- all it does is change the date on your submission, moving it to the bottom of the list if an editor sorts by date (assuming you're submitting to the same category each time; if you keep resubmitting to different categories, yes, that could be annoying to editors and could eventually be considered spammy).
I know it takes time for sites to appear in DMOZ, but am just concerned about the length of time that has passed.
Several months is not abnormal, unfortunately. FYI: to get a status here, it really helps if you follow the instructions in the forum guidelines and give a "clickable" link to the category. This category in particular is not heavily edited and so is extremely backed up -- I can't even begin to load the queue for that category, it's so big. It's going to be a long, long wait there, I'm afraid. I can see that you also submitted to
http://dmoz.org/Business/E-Commerce/Customer_Relationship_Management (where you are waiting for review with a slightly smaller number of other sites) and
http://dmoz.org/Business/E-Commerce (where you were deleted).
Please don't resubmit. Given the backlogs in the areas you've submitted to, I'd wait at least 3 months before coming back to this thread to ask for a status check.