I recently posted a pdf of a sign syllabary here on Maya Decipherment, under the new header category “Glyph Resources.” A number of other similar charts are available on the internet but many show a few small inaccuracies. This syllabary only displays the principal variants of some signs and is in no way exhaustive; due to space constraints it omits some less common or obscure variants and forms.
The signs more-or-less reflect the style and paleography used by Maya scribes in the Late Classic period, around 700 A.D.
This is “Version 2” of the chart, slightly modified from one I prepared for the Sourcebooks of the UT Maya Meetings in 2005. I plan to update the syllabary form time-to-time as new readings or other changes come along.