I am quite new to this, so please excuse my potential ignorance.  URL:
http://www.n10-central.com and I have used Dreamweaver to build the
290 page site.

I have a question regarding the renaming of files that have spaces in
them.  I now know that this was a mistake after I noticed that Google
has flagged that my xml sitemap has an error message. I believe that
this due to the fact that about 40 of my file names have spaces in
them.  I have started to change the names of these files (I have not
yet resubmitted the sitemap), but am now wondering what the impact of
this will be on the ranking of my website.  For example, one of the
pages (www.n10-central.com/o baby.html) has a ranking of 2, even with
the space in the name, others also appear on the first page.  I
certainly don't want to lose these positions.

Should I keep two copies of the "space" files on the server (eg. the
original "/o baby.html" and the revised "/o_baby.html") for a while,
and resubmit a new sitemap including only the revised file names?
That way the already ranked files will still be able to be accessed
until the renamed pages get indexed.

Or is there some trick that I can do to avoid having two copies of the
same file on the server?  (Or does this require me to take a serious
programming course?!?).

Or, should I just leave the spaces in file names as they are, as it
hasn't seemed to have done much harm to the example I gave above?

Many thanks in advance for your advice.

Regards,