I'm no FR guru, but I do know my way around the tome of battle. So...
For Swordsage, you're unquestionably awesome at being a mobile combatant. You don't have the HP pool of a primary combatant (Crusader!), so try to avoid being the main tank unless you've pumped your AC and maybe have some sort of miss chance (Child of the Shadows!). The only feat that is required on pretty much every Swordsage build is Adaptive Style, because the Swordsage recovery mechanic is absolutely atrocious.
Other than that general guideline though... What schools do you want to focus on? Setting Sun lets you bring some battlefield control to the table, while Desert Wind lets you hit the entire battlefield (usually considered a subpar tactic here, and since Fire is the most resisted of damage types... be warned). Tiger Claw is great for two weapon fighting. Shadow Hand is awesome for debuffing. Diamond Mind is a school that no one should ignore completely, because it has the great ability to replace a fortitude save with a concentration check (Mind over Body, l3), and other wonderful things like the ability to make a touch attack (Emerald Razor, l2) and the ability to have a massive number of attacks (Avalanche of Blades, l8). Lastly, Stone Dragon isn't a school to focus in, but it does have excellent utility in things like breaking through walls, gaining some DR and immobilizing (or otherwise removing actions) from enemies.
If you specify here, myself or someone else can give you more Swordsage advice.
