Winter may not be the time for gardening outdoors in most of the country, but it is the time of year to start dreaming about plants and gardens by getting seed catalogs in the mail or going to flower shows or going to garden symposiums and lectures.
One website that claims they list over 500 Garden shows in the US in 2015 and also tells you where to get tickets is this.
A good website to find 70 free seed and plant catalogs is this.
Every botanical garden in the country and most of the great gardens have outstanding lectures on plants, horticulture, gardening, you name it related to your garden or indoor plants. Check their list of programs to see if there is a talk that interests you. Wikipedia has a list of the major botanical gardens and arboretums in the US. You can then go on the website of the place that interests you or find their phone number to call to see what talks or garden programs they will be having in 2015.
Happy garden dreaming.