Ok, first off, this is NO WHERE near as hard as Guitar Hero III's Expert career. If you've completed that, you should have no problems on this at all. If you haven't however, then proceed to read further down.
Hammer-Ons/Pull-Offs - These are noted differently in Rock Band than the Guitar Hero series. In Rock Band, a hammerable note consists of a large note, followed by a noticeably smaller note. The smaller note needs not to be strummed, only pressed as it crosses the bar.
Fender Controller - If you are lucky and have a working Fender controller, you will notice that sometimes when playing the scrolling fretboard glows blue and a percentage comes up. That means you have entered a solo. On the Fender controller only, you can use the lower set of fret buttons during this time and can finger tap your way through the section without strumming. Just press the button as the note scrolls over the bar.
Timing Window - The timing window for Rock Band is a mix between Guitar Hero I and Guitar Hero II in my opinion. It is insanely tight. This means that you have about 3/4 of a second in any direction to hit the note as it crosses the bar. If you understand this concept, solos will come a little easier to you.
Ok, on to songs.....
Foreplay/Long Time- This song is probably the best in the game in my opinion, but that's besides the point. Basically this song consists of multiple chord switches in the beginning, followed by random solos after ever verse later on. The solos aren't ridiculously long or hard in anyway, but they can be a nuisance if you aren't expecting them.
Highway Star - This song is very deceiving to most people. It gives the impression of a steady rhythm, however it then turns into a really strong solo. I personally have been a fan of Deep Purple for 10 years, so I was aware of this. In the solo, there is a section where it breaks down into GG OO GG BB GG YY GG RR GG OO, etc... very Misirlouesque. This is on kind of an offbeat, and can be a very annoying section unless you get the timing down. I suggest practicing this part, and you should be very well off.
Flirtin' With Disaster - This song has an extremely strange rhythm and I have still not figured it out even though I've gold starred it. No matter, it's pretty straight forward. The verses consist of chord to single note switches followed by random breakdowns. There is one main solo that consists of blue to green lines then weird transfers back to blue. This is probably one of the most problematic parts of the song, because the lines aren't equally spaced. Again, I suggesting practicing this part, it will save you a few minutes of redoing the song because you didn't expect it.
Run To The Hills - Ok, this song is ridiculous. It is basically nothing but insanely fast triplets with a solo in the middle. The triplets of course are chords. They go something like Y-O to Y-B to R-B or something. That is the main rhythm of the song. If you can do triplets, and do them fast, this should give you no trouble. The solo basically consists of alternating notes (I.E. B O B O B O B O B Y B Y B Y etc....). Not too troublesome compared to the rhythm.
Green Grass and High Tides - Can you say Freebird? Everything about this song is reminiscent of Guitar Hero II days. It has a catchy southern beat with two main solos I believe. The rhythm is pretty straight forward, with your average chords and single notes. The first solo is nothing to "fret" (I made a funny) about, but the second one is. Our good ol' buddy Solo C comes back. That means rapid blue to red then back to blue zigzags up the fret board. It does this for b-r and y-g. They aren't that bad, but you may want to practice them because they are a good chunk of that solo.
**Stackable** meaning completion of this will unlock all subsequent achievements