The best list is at http://www.jlptstudy.com, just click on the level 4 list for grammar.
On items I do not understand, I check Renshuu, if I cannot find it, I go to
http://www.guidetojapanese.org/learn/grammar . I will also reference my handbook (Genki 1).
Ironically I found my grammar retention greatly increased by doing past jlpt 4 tests and seeing it in context.
Apologies as I do not have japanese installed on this machine :
te+kudasai = please do (tabete kudasai)
te+kudasai+masenka= won't you do x? (Tabete kudasai masenka?)
These two are the same, but the second one is more polite.
naide + kudasai = Please don't (tabenaide kudasai)
the o+kudasai is please give me (as in NOUN o kudasai, noun can also be sore (that), kore(this) o kudasai). They use this all the time in the listening to throw you off.
Mashou = won't you do this with me/us? (tabemashou? - stem+mashou)
Deshou = Isn't it or Probably ( oishii deshou? - Can be anything + deshou)
(I added deshou because I tend to mix them up conjugation wise)
Masenka = won't you do this with me? (tabemasenka). This one always throws me off in listening, because you hear MASEN, which is usually negative.
Also check out SHIKA (+neg verb) and DAKE, they change the whole sentence around, very tricky especially during listening (eg, I want a green hat and a black hat and the reply will be oh Midori shika arimasen, which means there is only a green one, they dont have the black one, not there is no green one).
Please double check anything I wrote as I'm a beginner myself. And I totally understand your stress, I'm getting pretty nervous already for the jlpt4 and it's 2 more weeks!
