Hmmm, this sounds like a job for Sketch Up…(cue super hero theme song…:-)
Sketchup is a computer aided design program which would allow you to create a drawing for your podium…but it may take you too long to learn it for just this one project (but it is worthwhile to learn for all the other projects you may find yourself doing).
You may want to just experiment a little. Zuki is right it does depend on what/where the podium will be used. To get the rough dimensions it may be as simple as holding the crossed 2bys in place with clamps and marking with a pencil where they cross (once you’ve got the height worked out for the table and slanted platform. Then mark these spots on your 2bys and then route out your dado (grooves) for the intersecting pieces. This is really not as difficult as it looks in text, play around with the wood and the ideas will start to flow….don’t be afraid to experiment a little.
Welcome to LumberJocks, I’ve only been here for a couple of months and have learned an enourmous amount and really appreciate what a knowledgeable and cooperative community this is…I hope you find it equally helpful.
-- ....next big purchase is wood for the next project, Mark