I'm currently a college student taking Organic Chem and I've no idea how to figure out the J-coupling for H-NMR and neither my professor/TA's/book are being helpful. Does one apply the n+1 rule first to figure the number of peaks and then apply the various couplings to each peak?

I understand that if a single H has two non-equivalent neighboring protons, you'd get a doublet of doublets instead of a triplet. But say, for example, how would I figure out the signal for the hydrogens attached to the terminal C of the double bond in 1-pentene ( the first carbon in, CH2=CHCH2CH2CH3)?

Thank you very much for your time.