Note: These links are provided for the information within them, and may use very gendered and especially feminized language. Unless it's very obvious I do not audit websites for trans-friendliness, so please view these at your own risk.
Information and Tracking Resources
This is a great site that lets you track your periods as well as related symptoms so that you can get a good feel for how long your cycle is (really important if you're trying out any pre-menstrual supplementation or if you just want to make sure you have your cup or pads with you when it comes!).
This is a heavily gendered site but it has a lot of menstruation-related information, including controlling when your period comes.
Natural Liberty: Rediscovering Self-Induced Abortion Methods (Sage-Femme Collective)
Despite the title, this isn't just about abortion but about cycle management (of which abortion is just a part).
Menstruation Products and Supplies
MenstroCup Menstrual Cup
This is my preferred menstrual cup, very similar to a DivaCup (similar size, texture, and stem) but much less expensive at about $13.
Babyville Boutique Packaged PUL Fabric, Boy Solids
PUL fabric is fabric with a coating on one side that makes it waterproof. This can be used to either create your own cloth pads (just line the side nearest your underwear with it) or to modify a pair of underwear to be leak-safe.
Menstruation Related Herbals
Yogi Teas Woman's Moon Cycle Organic Tea, 16 Count
This is a gendered product but if you're looking for a pre-packaged tea for menstrual symptoms this one has some common related herbals like dong quai and chaste berry.