To start off, some of my favorite Renoise tools. For reference, I produce lofi hip hop and DnB.
Groove Control>http://www.renoise.com/tools/groove-controlThis will help you achieve that groovy swing/shuffle.
Easy Tune>http://www.renoise.com/tools/easy-tuneMakes detecting the pitch of a sample a piece of cake.
Slice My Pitch Up>http://www.renoise.com/tools/slice-my-pitch-upAdvanced sample slicing power.
Akaizer>http://www.renoise.com/tools/akaizerAchieve that oldschool grainy-sounding time-stretching that old Akai samplers featured.
Rubberband timestretch and pitch-shift>http://www.renoise.com/tools/rubberband-timestretch-pitch-shiftGreat time stretching and pitch shifting. Notable for letting you stretch according to lines, beats, seconds or percentage.