Yes, the trail is straight forward. Get a map (San Jacinto Wilderness by Tom Harrison Maps) and pay attention to the signs on the trail, and you can't go wrong. Rarely the trail signs are missing (vandalism

), in which case you should consult the map.
A couple of miles into your hike on the 1st day you will come to Saddle Junction where there is a "hub" of trails. I believe some of the signs are in/on trees, and you will want to veer left.
When you get to the ".3 mi. to San Jacinto Peak" sign the trail gets fuzzy, but basically you just go UP. There is a rock scramble to the top. Usually there are other hikers you can follow if you're not sure.
The last 2 signs you need to keep an eye out for are on the Deer Springs Trail: the one on the right that will take you to Fuller Ridge (on your 2nd day day-hike); and the Strawberry Junction/ PCT trail that you will need to take to get back to your car at Humber Park.