I agree with Danny. a ? within your URL is fine. However, it is a good idea to minimize the length of characters after the question mark. Also, it is probably a good idea to avoid using the term 'id=' after your question mark.
Short Query String
Some sites use a very long set of variables and data after the question mark, such as in the following example.
<a href="/page.php?var=1&var2=2&var3=3&var4=4&var5=5&var6=6&var7=7&var8=8&var9=9&var10=10&var11=11&var12=12&var13=13&var14=14&var15=15&var16=16...">
Where the URL is:
/page.php?var=1&var2=2&var3=3&var4=4&var5=5&var6=6&var7=7&var8=8&var9=9&var10=10&var11=11&var12=12&var13=13&var14=14&var15=15&var16=16...
Google does not like the longer URLs, with multiple variables because it sees them as possible GET form posts.
Instead stick with just a few vars.
Avoid ID=
Google has stated in the past that the term 'id=' should be avoided in a query string. So it is a good idea to avoid it. That being said, I have seen many pages with that term that have been spidered.
Instead of the URL '/page.php?id=27' it is better to make it '/page.php?page=27', or similar. Or even better, '/page.php?page=jelly beans'. Using keywords is much better than numbers.