2nd Gear stiff

[LeFrog]

Engaging second gear on my 5 speed manual box is a tad difficult. There is no crunching, it's just stiff - enough to make you think about it when changin gear. I've only done 30,000 miles.
I'm wondering whether I need to look at the gear linkages.

[Kowalski]

Gear linkages are a good place to start but I'd also check gear box oil level too and perhaps change the oil regardless.