diff --git a/common/heap.go b/common/heap.go
new file mode 100644
index 00000000..dd2497b7
--- /dev/null
+++ b/common/heap.go
@@ -0,0 +1,87 @@
+package common
+
+import (
+    "container/heap"
+)
+
+type Heap struct {
+    pq         priorityQueue
+}
+
+func NewHeap() *Heap {
+    return &Heap{pq:make([]*pqItem, 0)}
+}
+
+func (h *Heap) Len() int {
+    return len(h.pq)
+}
+
+func (h *Heap) Push(value interface{}, priority int) {
+    heap.Push(&h.pq, &pqItem{value:value, priority:priority})
+}
+
+func (h *Heap) Pop() interface{} {
+    item := heap.Pop(&h.pq).(*pqItem)
+    return item.value
+}
+
+/*
+func main() {
+    h := NewHeap()
+
+    h.Push(String("msg1"), 1)
+    h.Push(String("msg3"), 3)
+    h.Push(String("msg2"), 2)
+
+    fmt.Println(h.Pop())
+    fmt.Println(h.Pop())
+    fmt.Println(h.Pop())
+}
+*/
+
+///////////////////////
+// From: http://golang.org/pkg/container/heap/#example__priorityQueue
+
+type pqItem struct {
+    value       interface{}
+    priority    int
+    index       int
+}
+
+type priorityQueue []*pqItem
+
+func (pq priorityQueue) Len() int { return len(pq) }
+
+func (pq priorityQueue) Less(i, j int) bool {
+    return pq[i].priority < pq[j].priority
+}
+
+func (pq priorityQueue) Swap(i, j int) {
+    pq[i], pq[j] = pq[j], pq[i]
+    pq[i].index = i
+    pq[j].index = j
+}
+
+func (pq *priorityQueue) Push(x interface{}) {
+    n := len(*pq)
+    item := x.(*pqItem)
+    item.index = n
+    *pq = append(*pq, item)
+}
+
+func (pq *priorityQueue) Pop() interface{} {
+    old := *pq
+    n := len(old)
+    item := old[n-1]
+    item.index = -1 // for safety
+    *pq = old[0 : n-1]
+    return item
+}
+
+func (pq *priorityQueue) Update(item *pqItem, value ByteSlice, priority int) {
+    heap.Remove(pq, item.index)
+    item.value = value
+    item.priority = priority
+    heap.Push(pq, item)
+}
+
diff --git a/docs/README.md b/docs/README.md
new file mode 100644
index 00000000..56dcea0a
--- /dev/null
+++ b/docs/README.md
@@ -0,0 +1,3 @@
+## Reading list
+
+* https://cryptonote.org/whitepaper.pdf